CLEVELAND, Ohio — Bariatric surgery significantly reduces several risk factors for cardiovascular disease and improves the structure and function of the heart, according to the largest-ever meta-analysis of the subject involving almost 20 000 patients followed up for a mean of almost five years .
"The magnitude of effect on cardiovascular risk factors is impressive, and to date no pharmacological therapy for weight management or diabetes has shown a comparable effect over these short time periods," say Dr Amanda Vest (Cleveland Clinic, OH) and colleagues in their paper published online October 167, 2012 in Heart. "These observations have elevated bariatric surgery beyond the realms of a cosmetic procedure and into the spectrum of interventions demonstrating efficacy in preventing CV events."
The researchers stress, however, that "the next step" should be to move from risk factors to routinely collecting data on long-term (>10-year) actual cardiovascular events, cardiovascular deaths, and all-cause mortality. Two of the 73 studies they included in their meta-analysis did this, including the longest report of bariatric-surgery outcomes to date from the Swedish SOS study, which demonstrated a 30% reduction in first-time CV events and an approximately 50% reduction in CV deaths in those who had surgery vs controls after almost 15 years of follow-up.
However, Vest et al stress that SOS showed that it was the baseline degree of insulin resistance, rather than initial body-mass index (BMI) or the amount of weight lost, that was most predictive of CV benefit.
More Work to See How Bariatric Surgery Improves Cardiac Function
Vest and colleagues say the purpose of their review was to accurately gauge the impact of bariatric surgery on CV risk-factor reduction, using the most recently published data to expand on previous observations.
They examined studies published from January 1950 to June 2012.
Prior to the surgery, about 44% of the patients suffered from hypertension, 24% had diabetes, and 44% hyperlipidemia. After the surgery, 63% saw their blood pressure fall, 73% had an improvement in their diabetes, and 65% experienced improvements in lipids.
In an additional group of 713 patients who had bariatric surgery and echocardiography, there was a significant decline in the patients' left ventricular mass and improvements in the E/A ratio--a measure of the filling velocity of the heart (from 1.28 to 1.48 across 391 patients)--and isovolumic relaxation time, which improved from 84 to 72.9 ms.
"This systematic review provides useful additional information for the physician who is advising a patient with obesity on their future risk of adverse CV outcomes," say the researchers.
However they stress that further research is needed to explain exactly how weight-loss surgery improves cardiovascular risk factors and to better define which type of patient will benefit most from this surgery.
"While bariatric surgery is not without its own risks, it should be considered a life-saving surgery, particularly for obese patients with high cardiovascular risk," says senior author Dr James Young (Cleveland Clinic, OH) in a statement .
But UK Report Cautions That Bariatric Surgery Care Can Be Inadequate
Meanwhile, a new UK report says almost two-thirds of obese patients who have weight-loss surgery are not getting the best possible care. The problem is particularly acute among those getting operations in the private sector rather than on the UK's National Health Service (NHS) .
The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report examined 357 cases out of the 3280 bariatric-surgery patients identified over a six-month period in 2010. Care of patients was deemed "good" in only 32% of cases, and there was room for improvement in 60%. There were 50 patients who did not meet the NHS criteria for having bariatric surgery: a BMI over 40 or over 35 with other comorbidities.
A quarter of the people in the study had self-referred--gone to a clinic without seeing their GP--and nearly half had paid for the surgery themselves. Of the patients, 32% did not get adequate follow-up after surgery and only 29% had psychological counseling beforehand. Almost 20% of patients were readmitted to the hospital within six months, and 21 had to have a further operation.
"Bariatric surgery is a radical procedure with considerable risks as well as benefits," coauthor of the report, Dr Ian Martin (City Hospitals Sunderland NHS Foundation Trust), told the Guardian . "When we reviewed cases we found examples of inadequate processes from start to finish. Even the basics--such as giving patients dietary advice and education before decisions to operate are taken--were sometimes lacking."
NCEPOD is recommending improvements and calling for a code of conduct for weight-loss-surgery advertisements, which often play down the role of the individual in achieving success, says Martin.
Vest reports no conflicts of interest; disclosures for the coauthors are listed in the paper.
Heartwire from Medscape © 2012 Medscape, LLC
Cite this: Gastric Bypass Moves 'Beyond the Realms' of Cosmetic Surgery - Medscape - Oct 24, 2012.