Obesity paradox supported by new heart procedures study

03 Aug 2017 --- Research at University Hospitals of North Midlands NHS Trust (UHNM) in the UK has confirmed a link between elevated body mass index (BMI) and patients having better survival outcomes following percutaneous coronary interventions (PCI).

The research found that the BMI of patients undergoing PCI procedures has increased over time. It was also found that those patients with a higher BMI, specifically overweight patients, have far fewer complications and better clinical outcomes compared to either normal-weight or underweight patients.

The link between higher BMI and better clinical outcomes supports the obesity paradox. This is a medical theory whereby overweight patients tend to have better outcomes for a number of different cardiovascular conditions than either patients with a “normal” weight or underweight patients.

PCI is a non-surgical procedure used to treat narrowing of the coronary arteries, improving blood flow to the heart. This study on its outcomes, which was funded by UHNM Charity, looked at data from all PCI procedures undertaken in the UK between 2005 and 2013.

Professor Mamas Mamas, Consultant Cardiologist at UHNM and Professor of Cardiology at Keele University, led this research, alongside Dr. Eric Holroyd, Consultant Cardiologist at UHNM, and other colleagues from the Trust.

Professor Mamas said: “We have found that patients over time are becoming heavier and more obese. For many years fat tissue was considered an inert tissue, but we now know that it releases hormones and other substances that may have a protective effect on patients.

“The important thing to say is that patients shouldn’t try to become obese in the hope that it will improve their outcomes. The effect size of this study was small, and obesity is associated with significant problems such as cancer, diabetes development and cardiovascular risk, so patients should maintain a healthy weight.

“More work will be required to understand the obesity paradox, whether it is a real biological phenomenon or whether it is driven by unmeasured facts such as obese patients being younger and therefore healthier overall, compared to more elderly and frail patients that are underweight or of normal weight.”

The study, “The Relationship of Body Mass Index to Percutaneous Coronary Intervention Outcomes: Does the Obesity Paradox Exist in Contemporary Percutaneous Coronary Intervention Cohorts? Insights From the British Cardiovascular Intervention Society Registry,” is published in the journal JACC: Cardiovascular Interventions.