UK Edition
Skinny patients far more likely die after common heart treatments
Skinny patients are far more likely to die after common heart treatments than those who are overweight, a major study suggests.
Research on more than 1 million adults found those who were underweight were five times as likely as obese patients to die after a routine cardiac procedure.
Obese patients fared even better than those of normal weight, the study found, in a phenomenon dubbed “the obesity paradox”.
The findings, presented at the European Society of Cardiology Congress in Barcelona, come from a US study which tracked patients for 30 days after their procedure.
All had undergone cardiac procedures used to investigate and unblock narrowed arteries.
Around 100,000 such procedures which go on to use balloons and stents to keep the arteries open are performed in England each year.
The study found that patients who were underweight had far greater risks than other patients - with the highest rates of readmission, the longest lengths of stay and the highest death levels.
Overall, those who weighed too little had death rates of six per cent, compared with a rate of 2.3 per cent among those of normal weight, and 1.7 per cent among those who were overweight.
The lowest rates of all - at 1.2 per cent - were among those who were obese.
The study tracked more than 1 million patients who underwent cardiac catheterisation, an investigative procedure, which in 42 per cent of cases was followed with the insertion of a stent or balloon.
The research did not establish why those carrying excess weight fared so much better.
One theory is that larger people have greater energy reserves to beat their illness.
Experts also believe that being underweight could be a symptom of poorer health, and that such patients might be more likely to be given too high a dose of drugs with bleeding risks.
Lead author Dr Afnan Tariq, an interventional cardiology fellow, from Lenox Hill Hospital, New York, said: “The obesity paradox has flummoxed researchers for some time, and our research also flips the conventional wisdom that a higher BMI should portend a worse outcome.
“We found that the lower BMI group had worse outcomes across the board, including readmission, length of stay, cost, and mortality.”
He said evidence suggesting that excess pounds offered some protection after surgery was mounting up.
“Further research will certainly add to the growing body of evidence, but the scales seem to be tipping in favour of higher BMI patients having better outcomes than normal weight patients,” he said.
“This study also reinforces the notion that the frail, those with the lowest BMI, have the worst outcomes - suggesting that when it comes to cardiac catheterisation, the smaller they are, the harder they fall.”
Underweight patients were 18 per cent more likely than normal weight patients to be readmitted within 30 days, while overweight and obese patients had the lowest readmission rates, and were more than 10 per cent less likely to be readmitted.
The phenomenon is known as the obesity paradox because excess weight is one of the major risk factors for heart disease, and the NHS advises a healthy diet and lifestyle as one of the best ways to protect against the killer.
A healthy weight helps prevent and manage conditions like high blood pressure, high cholesterol, and type 2 diabetes which increase the risk of heart disease.
Dr Mike Knapton, associate medical director at the British Heart Foundation, said: "This intriguing paradox seems to suggest that overweight and obese patients have better outcomes following certain treatments for heart disease. But we know you are far less likely to get heart disease in the first place if you maintain a healthy weight.
“Being overweight increases your risk of a range of health issues so keep active, cut down on alcohol and eat a healthy balanced diet.”
