BNP-Guided Primary-Care Intervention Reduces HF Risk: STOP-HF

March 14, 2013

SAN FRANCISCO — Assessing and tracking brain natriuretic peptide (BNP) levels in patients at high risk for heart failure can reduce the long-term prevalence of left ventricular dysfunction and heart failure, as well as the incidence of major cardiovascular events, according to the results of a new study presented this week at the American College of Cardiology 2013 Scientific Sessions .

Dr Kenneth McDonald (St Vincent's University Hospital, Dublin, Ireland), who presented the results of the STOP-HF study, said the study included primary-care patients at high risk for future heart failure, with 69% of patients having hypertension and 27% having diabetes.

"What we're doing with this strategy is seeing if we can fine-tune this large patient population to determine who is truly at risk, because the definition of hypertension and diabetes doesn't really help us," McDonald told heartwire . "The BNP test does. So it helps transfer this population, which is huge, into two dichotomized populations--those with an abnormal BNP signal and those with a normal BNP signal. For those with normal BNP, we have a slew of data showing that when it's low it's very reassuring. What we're seeing here is that if you use an aggressive cardiovascular program to look after people with a high BNP level, you can protect against the evolution of heart failure and the evolution of other cardiovascular abnormalities."

Dr Kenneth McDonald

In total, 1235 patients 40 years of age and older from 39 family practices in the southeast of Ireland were recruited to participate in the trial. All patients were asymptomatic but had at least one risk factor for left ventricular dysfunction or heart failure. All patients underwent annual cardiovascular screening, including screening for BNP levels. In the control arm, physicians were blinded to the BNP levels, whereas physicians in the intervention arm were able to use the BNP levels to guide patient care.

For patients with BNP levels >50 pg/mL, echocardiography was performed and the information shared with the family physician and the St Vincent cardiology service. In addition, there was an adjustment of patient risk for those with elevated BNP levels, with patients receiving cardiovascular-risk coaching and a review with the cardiology service.

After an average follow-up of 4.3 years, the primary end point, defined as the prevalence of left ventricular dysfunction and heart failure, was met in 59 of the 608 patients in the control arm (9.7%) and 37 of the 627 patients in the BNP-intervention arm (5.9%). This translated into a statistically significant 42% relative risk reduction in risk (p=0.013). Emergency hospitalizations for major cardiovascular events were also reduced with the BNP-guided treatment, down from 45.2/1000 patient-years in the control arm to 24.4/1000 patient-years in the intervention. This translated into a 46% relative risk reduction in the risk of cardiovascular hospitalizations.

Speaking during the late-breaking clinical-trials session, McDonald said the major difference between the control and intervention arms was in the use of renin-angiotensin-aldosterone-system (RAAS) therapy. At baseline, 40% of the control and intervention patients were receiving RAAS-modifying therapy, but in the intervention arm there was a 14% increase in the use of these drugs compared with an 8% increase in their use in the control arm. "Despite this, there was no difference in the behavior of blood pressure between the two groups," said McDonald. "Both groups showed, on average, a 10-mm-Hg reduction in systolic blood pressure."

In addition, the researchers note that approximately 50% of patients in the control and intervention arms were taking statins, and there was a similar increase in the use of statins over the study period. However, there was a significant difference in the reduction in LDL cholesterol during follow-up, which implies an improvement in adherence and compliance with statin therapy for those in the intervention arm.

"Patients in the intervention arm, as well as the primary-care physicians, were made aware of BNP," said McDonald. "It was explained to the patients that this was an indicator of cardiovascular damage and undoubtedly this led to an improvement in adherence to therapy. We also have some indirect evidence to suggest that this is the case, which is shown by the LDL-cholesterol result. We have no other explanation as to why the LDL was reduced in the intervention arm except for adherence."