Failure to prevent most heart failure could be avoided
More than 960,000 new cases of heart failure will occur in the United States this year – and most of them could have been prevented, asserted at Annual Cardiovascular Conference.
Preventing heart failure doesn’t require heroic measures. It entails identifying high risk individuals while they are still asymptomatic and free of structural heart disease – that is, patients who are stage A, pre-heart failure, in the American College of Cardiology/American Heart Association classification system for heart failure – and then addressing their modifiable risk factors via evidence-based, guideline-directed medical therapy, said by a professor of cardiovascular medicine and co-chief of cardiology. The top risk factors for the development of heart failure are hypertension and ischemic heart disease. Close to 80% of patients presenting with heart failure have antecedent hypertension, and a history of ischemic heart disease is nearly as common. Other major risk factors include obesity, diabetes, smoking, dyslipidemia, metabolic syndrome, and renal insufficiency.
A special word about obesity: A Framingham Heart Study analysis concluded that, after other cardiovascular risk factors are controlled, obese individuals had double the risk of new-onset heart failure, compared with normal weight subjects, during a mean follow-up of 14 years. For each one-unit increase in body mass index, the adjusted risk of heart failure climbed by 5% in men and 7% in women, And that spells trouble down the line.
Members of the writing group for the ACC/AHA guidelines on management of heart failure, recommend as a risk reduction strategy identification of patients with stage A pre-heart failure and addressing their risk-factors: treating their hypertension and lipid disorders, gaining control over metabolic syndrome, discouraging heavy alcohol intake, and encouraging smoking cessation and regular exercise.
What kind of reduction in heart failure risk can be expected via these measures?
More than a quarter century ago, the landmark SHEP trial (Systolic Hypertension in the Elderly Program) in more than 4,700 hypertensive seniors showed that treatment with diuretics and beta-blockers resulted in a 49% reduction in heart failure events, compared with placebo. And this has been a consistent finding in other studies: A meta-analysis of all 12 major randomized trials of antihypertensive therapy conducted over a 20 years period showed that treatment resulted in a whopping 52% reduction in the risk of heart failure.
If you ask most people why they’re on antihypertensive medication, they say, ‘Oh, to prevent heart attacks and stroke.’ But in fact the greatest relative risk reduction that we see is this remarkable reduction in the risk of developing heart failure with the blood pressure treatment.
There has been some argument within medicine as to whether aggressive blood pressure lowering is appropriate in individuals over age 80. But in HYVET (Hypertension in the Very Elderly Trial) conducted in that age group, the use of diuretics and/ or ACE inhibitors to lower systolic blood pressure from roughly 155mm Hg to 145 mm Hg resulted in a dramatic 64% reduction in the rate of new-onset heart failure.
How low to go with blood pressure reduction in order to maximize the heart failure risk reduction benefit? In the SPRINT trial (Systolic Blood Pressure Intervention Trial) of 9,361 hypertensive patients with a history of cardiovascular disease or multiple risk factors, participants randomized to a goal of less than 120 mm Hg enjoyed a 38% lower risk of heart failure events, compared with those whose target was less than 140 mm Hg.
(To be continued)