Gregory M. Weiss, MD

Hypertension disorders of pregnancy (HDP) are serious conditions that affect nearly one-quarter of all pregnancies and are currently the leading cause of perinatal maternal death around the world.

 It was previously known that HDP were associated with increased risk for cardiovascular disease (CVD) as far out as 20 or more years after the pregnancy, however, short term risk had yet to be defined.

Gestational hypertension or preeclampsia is defined as persistent elevated blood pressures during pregnancy and may put the lives of the mother and baby at risk in the short term. A great deal of focus has been put on the acute treatment of HDP due to the potential for loss of life prior to or even after delivery of the infant. The period over the next ten years following delivery has not been studied extensively.

Lisa Levine, MD, and colleagues sought to describe the prevalence of cardiovascular disease among women with HDP as compared to those without over the ten-year period following their pregnancy.

 The authors compared 84 patients with a history of HDP with 51 who did not.

 Of special note, 85% of participants were of African American race.

The results of the study revealed that women who experienced a HDP were 2.4 times more likely to experience new hypertension over the next 10 years compared to women who did not.

 Interestingly, while HDP predisposed women to hypertension, there was no increased risk for other CVD risk factors such as diabetes and no differences in key cardiovascular tests such as echocardiography and endothelial function tests.

What these results mean is that simply suffering from a hypertensive disorder of pregnancy puts a woman at risk for chronic hypertension within the next ten years.

 In addition to making this discovery, the authors noted that many of the women enrolled, including those who developed HDP and those who did not, may have had undiagnosed stage 1 or 2 hypertension prior to becoming pregnant.

This realization underscores the need for better screening and diagnosis regardless of pregnancy.

“[This study] along with studies with similar findings, further highlights the importance of routine screening for hypertension in this population,” Levine added. “Future studies should evaluate the optimal time period to screen for postpartum hypertension and a monitoring plan for these at-risk women.”

One important difference between this study and prior investigations was the inclusion of a diverse racial cohort. A lack of racial diversity in prior studies made extrapolation to a greater population difficult at best. Too many studies lack such diversity, a fact that ignores the plain truth that many diseases, hypertension in particular, disproportionally affect people of color.

Although these results may seem intuitive the post-partum period may see many women slip under the radar especially if they have a relatively uneventful delivery. Because obstetrics is a specialty unto itself, continuity of care and referrals to general practitioners and in the case of new hypertension internists and cardiologists may be lacking. The first inclination of a new mother is to go home and take care of her baby. Nevertheless, this study uncovers an important opportunity that should not be missed by obstetricians. Knowing that hypertension during pregnancy places the parturient at twice the risk for short term hypertension thereafter necessitates referral and close follow up.

It is important for all patients including young mothers who are often taken for granted as being healthy to be screened and treated appropriately. We know that hypertension puts these women at risk for the same cardiovascular outcomes as the general population. Postpartum cardiovascular care should include a referral plan that includes the regular monitoring of blood pressures and treatment as needed ongoing.

Levine, L. D., Ky, B., Lewey, J., et al. Prospective evaluation of cardiovascular risk 10 years after a hypertensive disorder of pregnancy. J Am Coll Cardiol. 2022 Jun, 79 (24) 2401–2411

Articles

Dr. Gregory Weiss provides perspective on a recent study suggesting women with gestational hypertension were at an increased risk of chronic hypertension later in life. 

HDPs Linked to Worsened Risk of Chronic Hypertension Later in Life

Vaccines for COVID-19 have become a routine part of life all over the world since the end of the first year of the global pandemic. The rapid production and authorization of several vaccines with activity against COVID-19 lead to widespread vaccination across the globe and are largely responsible for dramatic reductions in hospitalization and death as a result of the novel coronavirus. 

Even before the rollout of the first batches of mRNA vaccines and then the more conventional vaccine types, reactions from the general public ranged from enthusiastic hope to frank skepticism and fear.

Despite significant trepidation about the speed with which the COVID-19 vaccines were produced, the first 2 were approved and distributed for use in December of 2020. While phase 3 clinical trials did not reveal any significant adverse events, anecdotal reports began to emerge from European centers that patients were suffering more thromboembolic events following COVID-19 vaccination.

 Jacob Dag Berild, MD, and fellow researchers in Norway, Finland, and Denmark sought to determine the association if any between 3 COVID-19 vaccines and post-vaccination clotting problems.

The 3 vaccines examined in this project included the 2 mRNA vaccines, BnT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna), as well as the ChAd0x1nCoV-19 (AZD1222 AstraZeneca) vaccine.

 The authors used national patient registers to identify hospital visits and admissions secondary to thromboembolic and thrombocytopenic complications.

Primary outcomes included relative rates of coronary artery disease, coagulation disorders, and cerebrovascular disease while secondary outcomes included coagulation disorders and cerebrovascular disease (intracranial hemorrhage, cerebral thromboembolic events, and cerebral vein thrombosis).

By vaccine type the following results were obtained:

In the month following vaccination 305 events of coronary artery disease, 226 events of coagulation disorders and 231 events of cerebrovascular disease were observed.

 Significant relative risk scores were seen for coagulation disorders including venous thrombosis, thrombocytopenia, and cerebral venous thrombosis.

In the month following vaccination 3359 cases of coronary artery disease, 1674 cases of coagulation disorders, and 3228 cases of cerebrovascular diseases were observed.

 The relative risk for coagulation disorders was 1.12, and for cerebrovascular diseases was 1.09.

 No rate increases were observed for coronary artery disease and only small rate increases were seen for cerebrovascular thrombosis and coagulation disorders; however, these increases were only seen in the oldest birth cohorts.

In the month following vaccination 399 cases of coronary artery disease, 177 cases of coagulation disorders, and 358 cases of cerebrovascular disease were observed.

 Relative risk scores over 1 were observed for all the main outcomes and rate increases were observed for most secondary outcomes with the exception of thrombocytopenia or purpura.

As with the Pfizer vaccine, the vast majority of outcomes occurred in the oldest cohort.

The authors performed post hoc absolute risk analyses and found that while the relative risk for adverse outcomes was significantly increased the absolute risk only amounts to 4.9 events per 100,000 doses of vaccine.1 This is a very important result. While any adverse events should be taken seriously these data mean that the vast majority of individuals receiving COVID-19 vaccination will be protected from hospitalization and death and not experience an adverse event.

In summary, the results Berild and colleagues obtained show that vaccination with AZD1222 (AstraZeneca) was associated with increased rates of hospital contacts for thromboembolic coagulation disorders, especially thrombocytopenia.1 In addition, an increased risk for cerebrovascular thrombosis was seen after vaccination with AZD1222 and was consistent and robust across all 3 countries studied.1 The authors also observed statistically significant increases in the risk of hospital contacts for thrombocytopenic and thromboembolic events after BNT162b2 and the mRNA-1273 vaccination.

 However, the risk was small compared with those after AZD1222 vaccination. Finally, with the mRNA vaccines, the national estimates varied, with increased risk observed only in the oldest cohorts, with sensitivity analysis checking underlying assumptions of the analyses being inconsistent at best.

A pair of main takeaways can be garnered from these data. The AstraZeneca AZD122 COVID-19 vaccine increases the risk for thromboembolic events while the 2 mRNA vaccines studied only do so to a much smaller extent and with less consistency. With continued doubt from the general public these results should show skeptics that the benefits sharply outweigh the risk. More research is needed to define the risk with mRNA vaccines. This study serves as a good foundation for further investigation while reassuring clinicians that we should continue to recommend full COVID-19 vaccination, especially for high-risk individuals.

Berild, J. D., Larsen, V. B., Hviid, A. et al. Analysis of Thromboembolic and Thrombocytopenic Events After the AZD1222, BNT162b2, and MRNA-1273 COVID-19 Vaccines in 3 Nordic Countries. 

. 2022;5(6):e2217375. doi:10.1001/jamanetworkopen.2022.17375

Dr. Gregory Weiss provides perspective on a recent study detailing the risks of thrombosis observed with different COVID-19 vaccines among patients from a group of countries in Europe. 

Studies Detail Thrombosis Risks Associated with Different COVID-19 Vaccines

It has long been known that thyroid hormone levels are linked to cardiovascular (CV) regulation and that hyper- and hypo-thyroid states are detrimental to CV health. What is less clearly understood is how the intensity of thyroid hormone therapy affects CV risk and mortality. 

The authors of this study sought to evaluate the association between thyroid replacement intensity and cardiovascular mortality by examining a large pool of data from the Veterans Health Administration database.

Josh Evron, MD, and colleagues looked at 705,307 adults who received thyroid replacement therapy.

 They found that 10.8% of those patients died of cardiovascular causes.

 Thyrotropin and Free T4 levels were gathered for all patients in the study to determine if therapy led to exogenous hypo-, euthyroid, or hyper-thyroid conditions. The authors used regression modeling to produce survival analyses with cardiovascular mortality from myocardial infarction, heart failure, or stroke representing the primary outcomes studied.

The results clearly showed that patients with exogenous hyperthyroidism (thyrotropin levels <0.1 mIU/L) and those with exogenous hypothyroidism (thyrotropin levels >-20mIU/L) had increased risk of cardiovascular mortality when compared to patients who remained euthyroid.

 The association between exogenous hypo- and hyper-thyroid states and mortality increase with higher or lower thyrotropin levels in the hypo- and hyper-thyroid ranges.

This study provides a unique perspective looking at cardiovascular risk based on a very common treatment, thyroid replacement therapy. When prescribing a replacement therapy, the goal of treatment is to achieve a normal level in vivo of whatever hormone you are replacing. This is not as easy as it seems.

Arriving at the appropriate dose takes time and requires frequent measurements of thyrotropin and free thyroxine levels. Even during stable therapy patient factors may change the response, absorption, and metabolism of thyroid hormone. Thus, the intensity of treatment the authors are talking about is a constantly moving target.

The results of this study highlight the importance of regular testing and a willingness among clinicians to put in the work. The authors found that allowing thyroid replacement therapy to fall short or overshoot has real consequences in the form of increased cardiovascular mortality.

This means lives are at stake. This is the essence of a modifiable risk factor. Only, in this case, the modification is not a behavior the patient exhibits but one the clinician is responsible for. The authors state that variability in free T4 levels and thyroid hormone dosage adjustment are inevitable and thus agree with my assertion that regular monitoring and small targeted adjustments are essential parts of not only good thyroid care but also cardiovascular risk mitigation.

These results and conclusions are underscored by the fact that cardiovascular disease is the leading cause of death in the United States. Even though this was an observational study, the results are robust.

An important feature of these results was the linear relationship up and down between the extent of hypo- or hyperthyroid intensity and CV risk. This gives clinicians some room to work while at the same time placing guard rails and warning signs on the limits of acceptability where over and undertreating are concerned.

More work is needed. While the authors have identified an area where we as clinicians can improve, they have also brought up a few new questions. It needs to be determined if there are sex differences in this effect. Further, the degree to which comorbidities were managed was not examined in this study. It is clear however, that tighter observation, monitoring, and intervention are in order with regards to thyroid replacement therapy.

Centers for Disease Control and Prevention. Heart disease. Accessed July 29, 2021. 

https://www.cdc.gov/nchs/fastats/heart-disease.html

Benjamin EJ, Muntner P, Alonso A, et al; American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics—2019 update: a report from the American Heart Association. Circulation. 2019;139(10):e56-e528. doi:10.1161/CIR.0000000000000659

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2792219

Dr. Gregory Weiss breaks down a recent JAMA study that provides estimates of the impact over- and under-treatment with thyroid hormone treatment on cardiovascular disease risk in a cohort of US Veterans.

Too Much or Too Little of a Good Thing: Thyroid Treatment and Cardiovascular Risk

ACC Guidance on Cardiovascular Consequences of COVID-19

The impact of the novel coronavirus (COVID-19) pandemic on the world has been unprecedented in modern times. While respiratory involvement is the characteristic presentation of infection with COVID-19, it has become increasingly apparent that cardiovascular complications are common as well. A diverse list of cardiovascular testing anomalies and complications have been reported and range from biomarker elevations and echocardiographic abnormalities to myocardial injury, thrombosis, and arrhythmias.

It also appears that long COVID-19 cardiovascular symptoms and laboratory findings may persist following acute illness and may include chest pain, shortness of breath, fatigue, palpitations and diagnostic results indicating myocardial injury in both symptomatic and asymptomatic COVID-19 patients.

 In light of these facts the American College of Cardiology (ACC) thought it prudent to issue guidance with regards to three specific areas of post COVID-19 cardiovascular care: Myocarditis and other Myocardial Involvement, Post-acute Sequelae of SARS-CoV-2 Infection, and Return to Play (exercise) for athletes after COVID-19.

Myocarditis is a term used to describe nonspecific inflammation of the heart muscle. It is often accompanied by symptoms such as chest pain, shortness of breath, and the feeling of palpitations. Clinically, patients with myocarditis may have variable presentations so the ACC workgroup chose to separate myocarditis into three diagnostic categories:

Possible myocarditis: Patients who are symptomatic with elevated troponin values and abnormal electrocardiographic and or echocardiographic findings but without positive cardiac biopsy.

Probable myocarditis: Features of possible myocarditis with follow-up biopsy within six months consistent with previous myocarditis.

Definite myocarditis: Features of possible myocarditis but with positive biopsy or cardiac resonance imagery.

Data suggests that men are at higher risk for COVID-19 related myocarditis. The workgroup recommends that patients with mild to moderate or deteriorating symptoms be hospitalized for close monitoring, follow-up testing, and treatment. Those with severe disease should be hospitalized at facilities with advanced heart failure programs and mechanical circulatory support availability.

While recognized, the development of myocarditis after a second mRNA COVID vaccine is rare. The ACC recommends that, unless contraindicated, anyone eligible for a COVID-19 mRNA vaccine should get one.

The mainstays of treatment for clinically significant myocarditis remain supportive. Beta-blocking drugs and angiotensin inhibiting medications may be used in less severe disease without significantly diminished heart function. Corticosteroids may be employed when confirmed inflammation is present. Patients in cardiogenic shock may benefit from extracorporeal membrane oxygenation (ECMO) support until the inflammation recedes. Cardiac MRI should be performed to evaluate long term damage after improvement.

Long COVID is defined by a constellation of new, returning, or persistent health problems lasting four or more weeks after COVID-19 infection.

 This condition appears to affect as many as 10-30% of infected individuals and is characterized by fatigue, tachycardia, and exercise intolerance. The ACC workgroup suggest that these patients should undergo evaluation from a cardiovascular standpoint with additional evaluation if a specific condition such as myocarditis is suspected. Management should be targeted to specific symptoms. A “downward spiral” has been recognized whereby patients who suffer from fatigue exercise less and spend more time in bed leading to a worsening of symptoms. The workgroup suggests that low level exercise be encouraged with non-upright or recumbent exercise being used to avoid worsening fatigue. Beta blocking medications may be employed for tachycardia and nonsteroidal anti-inflammatory drugs sparingly for chest pain without evidence of ischemia.

The workgroup has issued guidelines for the return to competitive sports and intense exercise training. The group recommends that athletes recovering from COVID-19 with ongoing cardiopulmonary symptoms or those requiring hospitalization undergo further evaluation with electrocardiogram, troponin assays, and echocardiogram. These athletes should abstain from exercise for three to six months if diagnosed with myocarditis. Cardiac testing is not recommended for asymptomatic athletes. These athletes should abstain from training for three days to ensure that symptoms do not develop. For those with symptoms, they may return to training once symptoms resolve. Repeat cardiac testing and cardiac MRI are not recommended once symptoms have resolved.

In conclusion, the ACC continues to set the benchmarks in cardiovascular care. In this recent consensus statement on the cardiovascular implications following COVID-19 infection, the college addresses post infections myocarditis, long COVID syndrome, and returning to play for athletes infected with COVID-19. While these guidelines will undoubtedly aid clinicians in caring for patients the workgroup co-chair, Ty Gluckman, MD, MHA, warns that the best means to diagnose and treat myocarditis and long COVID continues to evolve.

Gluckman, T. J., Bhave, N. M., Allen, L.A., et al. 2022 ACC Expert consensus decision pathway on cardiovascular sequelae of COVID-19 in adults: myocarditis and other myocardial involvement, post-acute Sequelae of SARS-CoV-2 infection, and return to play: A report of the american college of cardiology solution set oversight committee. J Am Coll Cardiol. Mar 16, 2022. Epublished DOI: 10.1016/j.jacc.2022.02.003

Dr. Gregory Weiss, a cardiovascular anesthesiologist, provides perspective into the American College of Cardiology's recently released guidance related to the long-term consequences of COVID-19, which includes information on myocarditis, return to athletics, and more.

ACC Guidance on CV Consequences of COVID-19, with Gregory Weiss, MD

Cancer and heart disease are the leading killers of women in the United States.

 Sex-specific cardiovascular disease (CVD) markers have become an area of focus in cardiology. Even though women generally have lower burdens of obstructive coronary disease they are at higher risk for heart attack as their presenting event and have a worse prognosis than men following myocardial infarction.

Mammography is a well-established screening tool for breast cancer. Current recommendations call for yearly screening mammograms to begin at age 45 with more frequent scans commencing at 55 years of age.

 With screening visits of any kind at a premium, any chance we get to screen for multiple health problems should be taken advantage of.

Around two-thirds of women attend their screening mammograms through all age groups with the exception of women in managed care who attend at a rate of 88.4%.

 While breast arterial calcification (BAC) is a common finding on routine mammograms, it has not been used as an indicator for further investigation.

Carlos Iribarren, MD, MPH, PhD, of Kaiser Permanente Northern California, along with colleagues sought to determine the association if any between BAC and atherosclerotic cardiovascular disease. To this end, the authors performed a cohort study of 5059 women between 60 and 79 years of age who had attended mammography screening during the study period. The primary outcome was incident hard atherosclerotic CVD in this population.

The results indicated that the presence of BAC on digital mammograms was independently associated with incident atherosclerotic CVD.

 In fact, Iribarren and his team found that women with BAC on mammogram had a 51% higher risk for heart disease and stroke than those without BAC.

 Further, women with BAC were 23% more likely to develop any type of CVD including stroke, heart failure, and peripheral arterial disease.

 While these results are promising the authors could find no dose-response association between total burden of BAC and atherosclerotic CVD.

Iribarren points out that currently there is no standard for reporting or grading BAC. The authors suggest that grading technology could be incorporated in next-generation mammography equipment using a technology currently used to examine aortic arterial calcification.

“We hope that our study will encourage an update of the guidelines for reporting breast arterial calcification from routine mammograms. Our study has moved the needle toward recommending routine assessment and reporting of breast arterial calcification in postmenopausal women,” Iribarren said.

It should also be noted that no new screening visits or increased radiation dosage would be necessary to implement a BAC reporting practice since women would already be attending screening mammography visits regardless of a new recommendation to include BAC in the report. These findings give clinicians a tool already in use to improve sex specific risk stratification.

“Research has confirmed the calculators we currently use to assess an individual’s 10-year risk of developing cardiovascular disease are not as accurate in women as they are in men. In our current study, we evaluated if breast arterial calcification, which can be easily seen on a mammogram, provides more information about a woman’s risk of developing heart disease,” Iribarren added.

Of note, while the authors found an association between the presence of BAC and risk for developing atherosclerotic cardiovascular disease, having no BAC did not translate into low risk for CVD.

 While BAC may emerge as an important screening tool for CVD more study is required before it’s routine use is adopted. 

“Optimal risk factor control is equally important for all women with and without breast arterial calcification,” said Sadiya Khan, MD, MSc, FAHA, a cardiologist at Northwestern University.

Virani SS, Alonso A, Aparicio HJ, Benjamin EJ, Bittencourt MS, Callaway CW, Carson AP, Chamberlain AM, Cheng S, Delling FN, et al.; American Heart Association Council on Epidemiology and Prevention Statistics Committee and Stroke Statistics Subcommittee. Heart disease and stroke statistics-2021 update: a report from the American Heart Association.

. 2021; 143:e254–e743. doi: 10.1161/CIR.0000000000000950

Iribarren, C., MD, MPH, PhD, Chandra, M., MS, Lee, C., PhD, et al. Breast Arterial Calcification: a Novel Cardiovascular Risk Enhancer Among Postmenopausal Women,

Oeffinger KC, Fontham ET, Etzioni R, Herzig A, Michaelson JS, Shih YC, Walter LC, Church TR, Flowers CR, LaMonte SJ, et al.; American Cancer Society. Breast cancer screening for women at average risk: 2015 guideline update from the American Cancer Society.

. 2015; 314:1599–1614. doi: 10.1001/jama.2015.12783

https://newsroom.heart.org/news/mammograms-may-provide-clues-about-womens-risk-for-cardiovascular-disease

Dr. Gregory Weiss expounds on recent data indicating routine mammography in postmenopausal women could help identify women at increased risk of cardiovascular disease based on breast arterial calcification.  

Predicting Cardiovascular Risk Using Routine Mammograms in PostMenopausal Women

With every new year come new hopes, resolutions, and hopefully progress toward meeting our goals. The cardiology community is no different.

However, while many look to drop a few pounds after the holidays or put a little money aside for the future our wish lists as cardiovascular clinicians are often lengthier and loftier by comparison. In a time when we all desperately need something to look forward to here are a few thoughts on what’s ahead in 2022.

The surgical care of patients with cardiovascular disease dates back to the 1960s. Many advances have been made over the decades including better myocardial preservation, longer-lasting bioprosthetic valves, and better preoperative and postoperative care. One of the most exciting advancements over the last two decades has been the introduction of routine transcatheter aortic valve implantations (TAVI). Initial research was focused on utilizing the procedure for only those at highest risk for complications from open valve replacement surgery.

Over the last 2 decades, investigators have studied the technique in lower risk populations. While we have known that patients with aortic stenosis and a tricuspid aortic valve that were of high or intermediate risk for open surgery had at least as good outcomes if not better when compared to surgery we are now seeing data in low-risk patients and those with bicuspid aortic valves. A recent study looking at TAVI for low-risk patients with bicuspid or tricuspid aortic valves showed that the risk for mortality and stroke at 30 days and at one year were comparable between groups.

The reason I am excited about this study is because open-heart surgery, while an effective treatment for aortic valve stenosis, involves longer hospital stays, more pain, a longer recovery, and the potential for a myriad of complications not seen with transcatheter techniques. I have personally participated in hundreds of these procedures and am awestruck each time as a patient with a life-threatening anatomic condition undergoes a relatively brief and painless procedure with simple sedation only to be essentially cured two hours later. While there are complications associated with TAVI the evidence suggests that it could be a game-changer going forward.

You may have read about the second thing I am most excited about this year. On January 7, 2022, surgeons at the University of Maryland successfully transplanted a heart from a genetically modified pig into a human recipient. I am old enough to remember Baby Fae who received a baboon’s heart back in 1984 but died 21 days later due to acute rejection of the organ. 

The technique was abandoned for nearly 30 years due to genetic incompatibility and the high risk for rapid rejection. Now, with the widespread use of CRISPR gene-editing technology doctors were able to remove genetic elements responsible for rejection while inserting six human genes that induce the organ's acceptance by the recipient.

 The pig heart was transplanted into a 57-year-old man with no other options. So far, he is recovering well with no signs of rejection. With more than 100,000 people waiting for an organ transplant in the U.S. today and over 6000 of them dying on the list each year, this innovation may be transformational.

It may be obvious why I am excited about this amazing breakthrough. But beyond the fact that countless lives could be saved it is the process that impresses me. As with most quantum leaps in science, this achievement is built on the back of decades of research with countless setbacks, enormous costs, and often a lot of heartbreak. I think of all the lost loved ones waiting and now those hoping. Dr. David Klassen, chief medical officer of the United Network for Organ Sharing states,

“This is a watershed event. Doors are starting to open that will lead, I believe, to major changes in how we treat organ failure.”

These two technologies have a common thread. Only through good science and rigorous study do we make groundbreaking discoveries. COVID-19 has taken the spotlight for two years now and put a shadow over almost everything. As clinicians, we are tired but hopeful. The reason we are hopeful is because hard work and science keep going and keep offering us light in the darkness.

Makkar RR, Yoon SH, Chakravarty T, Kapadia SR, Krishnaswamy A, Shah PB, Kaneko T, Skipper ER, Rinaldi M, Babaliaros V, Vemulapalli S, Trento A, Cheng W, Kodali S, Mack MJ, Leon MB, Thourani VH.Association Between Transcatheter Aortic Valve Replacement for Bicuspid vs Tricuspid Aortic Stenosis and Mortality or Stroke Among Patients at Low Surgical Risk. 

https://www.washingtonpost.com/science/2022/01/11/pig-heart-transplant-genetically-modified/

https://www.organdonor.gov/learn/organ-donation-statistics

https://www.nytimes.com/2022/01/10/health/heart-transplant-pig-bennett.html 

Dr. Gregory Weiss provides insight into what he is most excited about in the field of cardiovascular medicine heading into 2022. 