Adult Cardiac

STS 2023, SAN DIEGO — The best practices for tricuspid valve surgery gained definition Sunday at STS 2023 as experts took the first steps to end the tricuspid’s undeserved reputation as the “forgotten valve.” Qiudong (Kevin) Chen, MD, MS, research resident at Cedars-Sinai Medical Center Smidt Heart Institute in Los Angeles, California, presented the Richard E. Clark Memorial Paper, which demonstrated that: ·       For non-endocarditis-related tricuspid regurgitation (TR), isolated tricuspid valve repair is associated with a lower risk of operative mortality (in-hospital or 30-days post-operative) than valve replacement. ·       In the same population, beating heart surgery (repair or replacement) is associated with a lower risk of pacemaker implant, renal failure, and post-operative blood transfusions than surgery under cardioplegic arrest. However, no mortality benefit was identified. ·       Higher pre-operative Model for End-Stage Liver Disease (MELD) scores were associated with higher operative mortality, especially for patients with MELD scores 20 or above. Increased levels of tricuspid valve regurgitation are associated with worse survival rates, and operative mortality can be up to 11% in patients undergoing isolated surgery. Both these factors contributed to the need for this analysis on a larger population level in order to start uncovering optimal surgical strategies. Senior authors for this study were Dr. Michael Bowdish and Dr. Joanna Chikwe. Dr. Chen and his surgeon colleagues conducted their review using the STS National Database™, which he called a “powerful, comprehensive tool” that allowed his team to review procedural trends and volumes from 2012 to 2019 across the US. He noted several limitations in the analysis, including lack of long-term outcomes and incomplete etiology. From the Adult Cardiac Surgery Database, physician-scientists initially identified 14,704 patients who underwent isolated tricuspid valve surgery and further narrowed this to 6,507 patients with non-endocarditis-related tricuspid regurgitation, who were assessed in the study. Although tricuspid regurgitation is common, the study confirmed that this disorder is extremely undertreated. Tricuspid repair and replacement remain rare surgeries nationwide: the investigators found that 93% of US medical centers performed five or fewer of these procedures annually. A majority of procedures were conducted with patients under cardiac arrest, followed by surgeries on patients with beating hearts and a small minority performed on patients with fibrillating hearts. “I believe these findings suggest that in this patient population, tricuspid repair may be a safer option when feasible,” Dr. Chen said. He was joined by senior co-authors Michael E. Bowdish, MD, MS, Jad Malas, MD, and Amy Roach, MD, all also from Cedars-Sinai, in this study. “Surgical outcomes for isolated TR are poor, and we can do better by generating additional clinical evidence by identifying those patients with TR and operating on them early,” added James Gammie, MD, professor of surgery at Johns Hopkins Medicine, who served as discussant. Putting tricuspid regurgitation in perspective, Dr. Gammie noted that about 1.6 million people in the US have significant TR, making the disease almost as prevalent as aortic stenosis.

This scientific presentation covered in this article was part of the STS 2023 session “Perspectives from Asia: Aortic Disease, Coronary Disease, and Mechanical Circulatory Support,” and is available in Annual Meeting Online. Access or purchase it here. For Asian patients with aortic disease, determining whether to take a surgical or conservative approach to treatment may depend on much more than size. “Given my particular interest in aortic surgery and participation in the recently released American College of Cardiology/American Heart Association guidelines, I was asked to try to answer this question,” said Edward P. Chen, MD, from Duke University School of Medicine in Durham, North Carolina. “As I dug deeper, I found that the answer is considerably more complicated than a simple yes or no.” In terms of comparative studies, data that can help to quantify aortic disease risk can vary significantly in populations identified as “Asian,” Dr. Chen said. Even as body habitus fluctuates from region to region, the risk of adverse events may be based not only on the diameter of the aorta, but also aortic diameter indexed to both body surface area and height. “As it turns out, despite what I heard occasionally when I was growing up,  Asians do not all look the same.” Environmental and cultural factors throw another wrench: A patient who is a Japanese national, for example, might have a markedly different lifestyle than an ethnically Japanese patient living in the West. “When I was a medical student, for instance, I learned there was a high incidence of gastric cancer in Japan," Dr. Chen said. "But Japanese people living in the US have more colorectal cancer, which could potentially be explained by differences in both diet and environmental conditions.” The incidence of comorbid conditions—as well as access to health care—ranges widely in patient cohorts across the globe. When Dr. Chen began researching his presentation, he reached out to Dr. Kay-Hyun Park of Seoul, Korea, president of the Asian Society for Cardiovascular and Thoracic Surgery, for an additional perspective. Dr. Park’s blunt reply: “I (and probably any Asian surgeon) cannot represent the entire ‘Asia’ and deliver the ‘Asian perspective,’ because I have no means to grasp what they are doing in the other Asian countries.” Dr. Park added, “Even in my own neighborhood in Korea, their aggressiveness is quite varied.” He went on to say that, in areas where patients might have more limited access to state-of-the-art surgical care, a surgeon might err more aggressively on the side of surgery—not knowing when they might get to see that patient again. Acknowledging the limitations and complexity at work, Dr. Chen and his coauthors aimed to design the latest guidelines to assist the clinician in making the best decisions for each patient on a case-by-case basis. The presentation was part of a session hosted jointly by STS and the Asian Society for Cardiovascular and Thoracic Surgery, “Perspectives from Asia: Aortic Disease, Coronary Disease, and Mechanical Circulatory Support,” moderated by S. Christopher Malaisrie, MD, and Wilson Y. Szeto, MD.   “Shared decision making is going to be the key here,” Dr. Chen said. “Yes, we don't actually have all the answers. But what we should do is take the data we have and try to individualize it to every patient we take care of, and not have a uniform umbrella policy. Particularly here in the United States, with the potpourri of diverse ethnic groups we take care of, it’s important to use the guidelines along with the data we have, the patient’s known measurable anatomic factors as well as lifestyle considerations, and one’s own experience and clinical judgment to make the best decision possible for the patient.”

Tomorrow at STS 2023: A study of more than 100,000 patients reveals that, for patients with blockages in multiple arteries, those who opt for coronary artery bypass grafting (CABG) are less likely to die from their condition, less likely to need additional surgery, and less likely to have a heart attack than patients who choose to undergo a stent procedure. “The findings of our study were very convincing,” said J. Hunter Mehaffey MD, MSc, from the Department of Cardiovascular and Thoracic Surgery at West Virginia University. “The singular message to the public is that the optimal treatment for multivessel coronary artery disease—to improve not only long-term survival but also lower your risk of complications—is coronary artery bypass surgery.” The results from the study, “Contemporary Artery Bypass Grafting versus Multivessel Percutaneous Coronary Intervention in 100,000 Matched Medicare Beneficiaries,” will be presented at 9:05 a.m. PT on Sunday, January 22, during STS 2023. The background and rationale for this research project started with the publication of the 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization, Dr. Mehaffey explained. “The cardiac surgery world was really shocked, because the guidelines downgraded the indications for CABG from a class 1 recommendation to a class 2B.” “Much of this decision to downgrade was based on the guideline committee’s goals to focus on the most recent data, to ensure that they were capturing contemporary stent technology, so they only evaluated studies published within the past 5 years,” continued Dr. Mehaffey. “Therefore, these guidelines relied heavily on the recently publicized ISCHEMIA trial, which looked at medical therapy in coronary artery disease, comparing an initial invasive approach versus a conservative approach to patients who had stable coronary artery disease.” The problem that arises when using ISCHEMIA to compare CABG to stenting is that the majority of patients in the ISCHEMIA trial were not representative of patients undergoing CABG in the US. Therefore, the study didn’t fully represent the comparative benefits for patients who had multiple blockages in their coronary arteries.   Dr. Mehaffey’s team sought to conduct a large contemporary analysis that more fully represented this population, comparing patients undergoing bypass surgery with those undergoing stenting. They, too, wanted to ensure that the study included only the most contemporary technology, so their longitudinal analysis captured outcomes over a 3-year period, 2018 to 2020. “We used one of the largest and most inclusive databases of patients hospitalized in the US, including all patients over the age of 65 on Medicare,” Dr. Mehaffey explained. “We performed a very robust statistical analysis including propensity score balancing to help ensure that the groups of patients who underwent stenting versus those who underwent bypass surgery were well matched and well balanced in order to compare their outcomes.” The population included more than 100,000 patients with multivessel coronary disease, with 51,000 patients undergoing CABG and 52,000 undergoing stenting. Analysis was performed by a multidisciplinary team that included cardiac surgeons, cardiologists, and researchers at West Virginia University. The analysis demonstrated a significantly lower hospital mortality for the patients who underwent CABG compared to those who underwent stenting. Additionally, the researchers found a marked reduction in both 30-day and 3-year readmissions for myocardial infarction. CABG patients were also significantly less likely to need any additional stenting or intervention on their coronary arteries during those 3 years, and—most significantly—those who underwent CABG had a nearly 60% reduction in death at 3 years compared to those who had stenting. “Regardless of your specialty, these data demonstrate the importance of assessing longitudinal outcomes to help ensure we’re making optimal treatment recommendations for our patients,” Dr. Mehaffey said. MORE ON THIS TOPIC AT STS 2023 To fully understand the implications of the latest science--which demonstrates that CABG is superior to stenting in multivessel coronary artery disease, don't miss: C. Walton Lillehei Lecture by Peter K. Smith: "Treatment Selection for Coronary Artery Disease: The Collision of a Belief System with Evidence" Monday, 9:00 a.m. PT "The ISCHEMIA Study Does Not Reflect Patients Undergoing Coronary Surgery: An STS Adult Cardiac Surgery Database Analysis" by Joseph F. Sabik III, MD Monday, 11:30 a.m. PT

     

STS News, Fall 2022 — With nearly as many women as men presenting with signs of ischemia in today’s health care settings, clinicians should keep in mind that coronary artery disease (CAD) goes beyond vessel obstruction, especially in female patients—and should take advantage of tools like advanced imaging to see past anatomic walls. “More and more, I think we're recognizing that, when they’re designed for the identification of primarily obstructive CAD, conventional approaches can lead to repeated testing, especially in women,” said Viviany R. Taqueti, MD, MPH, from Brigham and Women’s Hospital in Boston, Massachusetts. “And yet, often without differentiating who’s truly at risk.” Obstructive CAD is just one phenotype of ischemic heart disease, and perhaps just the tip of the iceberg when physicians take into consideration the entirety of coronary circulation, Dr. Taqueti said. A physician needs to spot other pathologies such as diffuse non-obstructive CAD and coronary microvascular dysfunction, which can certainly impact patients’ cardiovascular outcomes, she explained. As an example, Dr. Taqueti referred to a study in Denmark that presented observational data from a large registry of more than 11,000 patients who were referred for coronary angiography. The investigators found that up to a 32% of the male patients—and a startling 65% of female patients—had no significant obstructive disease to explain their symptoms. “We need a more sophisticated toolbox that looks beyond regional wall motion abnormality or even regional perfusion abnormalities to consider and quantify absolute blood flow in the heart and quantify coronary flow reserve, or CFR,” said Dr. Taqueti. Coronary microcirculation is of course too small to be directly imaged in vivo, and it needs to be evaluated indirectly by perturbing function. A variety of technologies make this possible. Coronary microvasculature, especially in female patients, represents the future of prognosis after procedures like CABG, say experts. "Conventional approaches can lead to repeated testing, especially in women. And yet, often without differentiating who’s truly at risk.” Viviany R. Taqueti, MD, MPH In the invasive realm, historically, catheter-guided wire-based testing has provided measurements of CFR and microcirculatory resistance. But noninvasive methods, including cardiac magnetic resonance, Doppler ultrasound, and—the current gold standard—positron emission tomography, are revealing just how prevalent coronary microvascular dysfunction is in patients with angina or signs of ischemia. Data from more angiography studies demonstrated that just under half of the patients had no obstructive disease. “And these were evaluated quite objectively, using fractional flow reserve normal values above 0.8,” Dr. Taqueti explained. But from that group, a large majority—76% to 89%—had some evidence of objective coronary vasomotor dysfunction on testing. “The vast majority of these had coronary microvascular dysfunction, with a minority having pure vasospasm,” said Dr. Taqueti. “This is important because we know that impaired flow reserves—that can certainly be manifestations of coronary microvascular disease—are associated with worse outcomes in terms of cardiac mortality in our patients.” More revelations come with observational data that span multiple research centers: Even in patients with no obvious obstructive lesions or inducible ischemia on stress testing, impaired CFR is independently associated with major adverse events.  In those with significant obstructive CAD, CFR also modifies the outcome of coronary revascularization procedures, especially coronary artery bypass grafting (CABG), Dr. Taqueti pointed out. With long-term cardiovascular outcomes, patients with a severely reduced CFR who underwent CABG did as well as those with a preserved CFR to begin with (adjusted p for interaction = 0.03), suggesting that impaired CFR may serve as a marker for CABG benefit akin to diabetes or SYNTAX score, said Dr. Taqueti.     When severely impaired, coronary flow reserve is even more prognostically significant in women—and may be as useful of a marker for CABG benefit as diabetes or SYNTAX score. In women, severely impaired CFR appears to be even more prognostically significant. “You can see the divergence of the hazard for men and women with a significant interaction for sex as CFR values fall substantially below 2,” Dr. Taqueti explained. “Women appear to fare even worse at the very low range of CFR despite the fact that, when you look at anatomic findings, they are much less likely to have multivessel obstructive disease. In contrast, men were much more likely to have impaired CFR in the presence of multivessel disease—perhaps explaining their impaired flow reserves.” Dr. Taqueti encouraged physicians to consider how these factors reframe their approach to understanding CAD, and to emphasize appropriate diagnostic testing to identify risk, which can help to curb repeated conventional testing in patients at low risk. These recommendations were presented as part of the STS Coronary Conference this summer, in a session devoted to noninvasive diagnostic techniques for evaluation of high-risk ischemic heart disease. The conference united faculty and attendees from 18 countries with a multidisciplinary approach. Course director Marc Ruel, MD, MPH, who serves as STS Canadian Director, touted the camaraderie displayed by participants of all backgrounds. “Surgeons have to be the top experts at understanding the very reason why they operate—or not—on a patient,” Dr. Ruel said. “It comes down to much more than ‘I can do this,’; rather, it should be ‘It is a good idea to be doing this for the patient, and I have the skills to do it.’ The Coronary Conference aimed to achieve this: Expert knowledge and skills in the huge, knowledge-intensive area of coronary surgery.” Strong surgeons need strong cardiologists, anesthesiologists, radiologists, and other experts, Dr. Ruel said. “This is why we made the Coronary Conference so multidisciplinary and team-based, with a focus both on advanced practical knowledge and on advanced technical skills.” “We need to understand microvascular disease in order to better treat ischemia in both women and men,” Dr. Taqueti added. “Coronary microvasculature represents an exciting new frontier in cardiovascular disease reduction, and the future is pointing toward a role for coronary microcirculation in macrovessel disease prognosis. That’s something we need to think about in all our practices.”