By Kai Hill

Doctors sometimes delay open-heart surgery for people with obesity, concerned that excess body fat may complicate the results. But operating sooner rather than later can help reduce the risk of patients with obesity, especially women, dying in the hospital after mitral valve surgery, according to new research published in JTCVS Open.

A team working with Joseph Lamelas, M.D., chief of the Division of Cardiothoracic Surgery at the University of Miami Leonard M. Miller School of Medicine, analyzed one of the most recent and largest study samples yet of hospitals in the United States. Because mitral valve surgery is one of the most common open-heart procedures nationwide, the study examined outcomes for 48,755 patients with obesity who underwent mitral valve replacement or repair between 2012 and 2020.

The article, “Predictors of Outcomes in Patients with Obesity Following Mitral Valve Surgery,”  grew out of a study of hospital encounters from the National Inpatient Sample database, which was presented at the national Mitral Conclave workshop of the American Association for Thoracic Surgery.

Elixhauser Scores Associated with In-hospital Mortality

The authors applied regression and random forest analysis to the data. Random forest uses ensemble machine learning, including multiple decision trees, to tackle large, complex datasets without making overly strict assumptions about the predictive model.

The analysis used the Elixhauser Comorbidity Index, a model based on 31 comorbidities (such as liver and kidney problems) to estimate preoperative risk. The study found that a higher Elixhauser score — with more comorbidities — was the single-most important predictive variable of in-hospital postoperative survival.

Dr. Lamelas, a renowned pioneer in minimally invasive cardiac surgery known as the Miami Method, oversaw the team. He said the findings confirm his preference to perform the procedures on patients with obesity earlier, and as noninvasively as possible, to reduce potential complications, minimize use of resources and improve outcomes both for patients and the health system.

New Technologies Offer UHealth Interventional Cardiologists Greater Precision, Improved Patient Selection

One is software, one is a device, and both are helping cardiologists help people with blockages, restricted blood flow and microvascular disease around the heart.

The AI-powered software called HeartFlow (HeartFlow Inc.) interprets CT scans of the blood vessels around the heart. HeartFlow generates 3D images that can help identify any vessels that are fully or partially blocked, indicating that an individual might need to go to the catheterization lab for further workup. If blood flow appears normal, it could help spare a patient from invasive procedures to measure the flow. In this case, doctors might be able to treat some patients with medication instead.

“We could cut down on the number of diagnostic and basic procedures we do — and only refer patients in the most severe cases who would need further intervention,” said Carlos E. Alfonso, M.D., an interventional cardiologist at UHealth – University of Miami Health System.

The HeartFlow can also be valuable to help people avoid other unnecessary procedures. In the past, if someone had a “borderline lesion” on an angiogram, typically they were referred for a cardiac stress test or sent directly to the cath lab for invasive assessment. Because HeartFlow measures blood flow noninvasively, some patients might be able to forgo these types of interventions.

CoroFlow Directly Measures Blood Flow

If a patient is referred to the cath lab, a new tool called CoroFlow (Coroventis) can help get a more precise diagnosis. CoroFlow is a comprehensive physiology solution (hardware and software) that utilizes a thin coronary pressure wire, the Abbott Pressure Wire X. The wire is able to accurately assess flow impairment in both the visible coronary arteries, as well as the invisible coronary microvasculature, to assess for microvascular disease.

The CoroFlow could help when a patient has typical symptoms but does not have obstructive coronary disease. “We know that microvascular disease is something that occurs much more commonly in women than men. Up to 50 percent of women who have angina or anginal symptoms have been shown to have non-obstructed coronary vessels but could have microvascular disease,” Dr. Alfonso said. Therefore, the technology can facilitate a formal diagnosis and help physicians adjust treatment that could most benefit people with microvascular disease.