Bariatric Surgery’s Effect On Heart Dramatic:Study
Whistler, British Columbia—Bariatric surgery has been shown to improve cardiac function in 100% of morbidly obese patients, according to results from the first large-scale study of the topic.
“This is a very, very important study. It truly is a first,” said John Dixon, MD, senior research fellow, Monash University, Melbourne, Australia. “The paucity of information regarding weight loss and its effect on the heart is astounding. This is the first study, with any quality behind it, that shows the effect that obesity surgery can have on the heart.”
Bariatric surgery has already been shown to improve other comorbidities linked to obesity, such as diabetes, hypertension and sleep apnea, but its effects on heart function and structure have yet to be investigated in a large series of patients.
Researchers say that the better cardiac function could stand among the most significant improvements in the quality of life of morbidly obese patients, as well as dramatically extend their life expectancy.
“Numbers and pounds, kilos and estimated weight loss are all nice to look at but, in reality, our goal as bariatric surgeons should be to improve the quality of life for our patients,” said the study’s lead author, Keith B. Boone, MD, assistant clinical professor of surgery, University of California at San Francisco. “When patients have a noticeable difference in their basic level of cardiovascular fitness, their ability to move around, that makes a big impact on the quality of life.” He presented the findings at the 2004 annual University of Pittsburgh Medical Center Minimally Invasive Surgery symposium.
Dr. Boone retrospectively studied 500 consecutive patients (79% female; mean age, 50.7 years) who had undergone Roux-en-Y gastric bypass surgery. Of these, 78 underwent Doppler echocardiograms and provocative stress tests preoperatively and postoperatively. A single cardiologist analyzed the tests.
All patients except one had left ventricular hypertrophy (LVH) preoperatively. One year after surgery, LVH resolved in 94.5% of patients, with complete resolution in 54% of patients. Posterior wall thickness decreased an average of 1.9 mm+/-0.91 and interventricular septum decreased 1.7 mm+/-1.1. No patient had progression of LVH.
Dr. Boone said that the finding is significant because of the serious mortality risk associated with LVH. Data from the Framingham Heart Study, a 50-year study of the residents of a Massachusetts town, show that the risk of sudden death is five to six times higher in patients with LVH than in patients without, regardless of blood pressure level (Kenchaiah S, et al. N Engl J Med 2002; 347:305-313).
Dr. Boone’s study showed a sizable reduction in cardiac structure one year after surgery. Every patient had smaller left ventricular mass, with an average loss of 83.7 g. The postoperative range was 171 to 391 g, compared with 238 to 471 g prior to surgery.
In postoperative treadmill tests, all patients, except one, were able to walk for longer periods. Average walk times increased from 4.51+/-1.67 minutes to 6.96+/-1.8 minutes. “Patients were really encouraged by the cardiologist that they would be able to walk longer, but that was a real difference that they can see,” Dr. Boone said.
Today’s young generation may be the first in history to have a shorter life span than their parents because of obesity-related disease, he pointed out.
Dr. Boone’s group currently performs preoperative cardiac testing for all patients older than 50 and any younger patients with a history of cardiac events or symptoms, a strong family history of cardiac disease, a strong risk factor history, or abnormal cardiac exams performed by surgeons upon initial consultation.
Dr. Boone is currently studying another 50 patients who underwent preoperative cardiac testing, now being followed up. However, he said, their efforts are limited by difficulties in getting insurance company approval for postoperative studies.
Philip Schauer, MD, director of bariatric surgery, University of Pittsburgh Medical Center, said he hoped that Dr. Boone’s study, together with other research that shows bariatric surgery can resolve diabetes, depression and hypertension, will increase awareness of surgery as a primary treatment for morbid obesity.
He noted that recent publications on obesity management, from the American Diabetes Association and the New England Journal of Medicine, do not mention surgery as an option for morbidly obese patients.
The original article appeared in General Surgery News
ISSUE: MAY 2004 | VOLUME: 31:05