Medical Device Daily Staff Writer and Staff Reports
ATLANTA – John Batsis, MD, of the Mayo Clinic (Rochester, Minnesota) told a press audience Monday at the annual meeting of the American College of Cardiology (Bethesda, Maryland) that his institution's study of bariatric surgery in obese patients showed that it can serve as a pre-emptive strike against coronary artery disease. Those who underwent the surgery were determined to have a much lower risk than the control group for having a heart complication.
The Mayo team completed a historical study between 1990 and 2003 of 197 patients with Class II-III obesity that underwent Roux-en-Y gastric bypass surgery, compared to 163 control patients enrolled in a weight reduction program, with an average follow-up time of 3.3 years. In the study the team recorded changes in cardiovascular risk factors such as cholesterol levels, body mass index and diabetes criteria.
Though the researchers originally estimated a higher 10-year risk for cardiac events in the surgical group at the start of the study, due to their associated conditions, these patients had a much lower risk than the control group, or 18.3% vs. 30%.
Noting at the beginning of his discussion that 60% of the U.S. population is overweight or obese, Batsis cited the ACC's identification of obesity as a major contributor to heart disease and the prevalence of conditions such as hyperlipidemia and sleep apnea, also contributing to cardiac events.
“Cardiac disease is the most prevalent cause of death in overweight patients,“ Batsis said.
Using the study parameters and risk models based on previously published data, the team estimated that for every 100 patients, the surgery would prevent 16.2 cardiovascular events and 4.1 overall deaths, as compared to the control group. However, should the number of deaths during surgery approach 4%, the “protective effect is limited,“ as it may be in the case of centers with very low volumes of weight loss surgeries.
All patients underwent extensive behavior modification therapy for six months prior to surgery as well.
The team found that, at follow-up, the percentage of the surgery population meeting criteria for diabetes was reduced from 30% to 11%, followed by a 68% reduction in drugs for diabetes. Results also showed reductions in blood pressure of 26%, LDL cholesterol and body mass index (BMI).
“With an understanding of the very close link between obesity and cardiovascular risk, we feel confident that a procedure like bariatric surgery is an effective alternative to current therapies, which can have a considerable and lasting improvement in cardiac health,“ said Batsis. “For the patients who are eligible for surgery, this suggests a reduced risk of cardiac events or death.“
In other early presentations at the conference:
• Nickole Henyan, of Hartford Hospital (Hartford, Connecticut) discussed results from a study investigating the use of implantable cardioverter defibrillators (ICDs) and found that females have “significantly lower survival rates“ with this procedure than their male counterparts.
The study authors reviewed previous studies on ICDs and evaluated five trials that met specific criteria: controlled trial vs. standard of care; ICD as primary intervention and available data on risk of death for both male and female patients.
What Henyan and her co-authors found was that ICD therapy reduced the risk of death by 24% in men, but only by 12% in women.
“This study strongly illustrates that ICDs are not the ideal primary prevention method for treating potentially fatal arrhythmias in women,“ Henyan said.
• New findings from the UNLOAD (UltrafiltratioN versus IV Diuretics for Patients HospitaLized for Acute Decompensated Congestive Heart Failure) study detail immediate and long-term benefits for heart failure patients receiving ultrafiltration therapy to treat fluid overload.
In the UNLOAD trial, ultrafiltration was administered via the Aquadex FlexFlow, a system manufactured by CHF Solutions (Brooklyn Park, Minnesota).
CHF describes UNLOAD as the first randomized clinical study to compare the safetyand efficacy of a non-drug-based option with standard intravenous diuretic drug therapy to treat heart failure patients.
Two hundred patients were enrolled at 28 sites. In this prospective trial, patients were randomized and placed in either the ultrafiltration group or the intravenous diuretics group, and assessed at entry and at intervals out to 90 days.
At 90 days, the ultrafiltration group had significantly fewer days in the hospital, rehospitalizations for heart failure, unscheduled heart failure office visits and emergency room visits.