SAN FRANCISCO – Targeting a comprehensive cardiac-risk reduction program to adults with elevated natriuretic peptide significantly cut the rate of new left ventricular dysfunction, heart failure, and other cardiovascular events in a randomized trial with more than 1,300 patients.
"I think it was the structure of the intervention, the cohesion of care, rather than a specific intervention" that improved clinical outcomes, Dr. Kenneth M. McDonald said at the annual meeting of the American College of Cardiology. "Undoubtedly, a patient’s knowledge [of a high B-type natriuretic peptide level] improved their adherence to therapy." He and his associates ran the study at 39 primary care practices around Dublin that worked in collaboration with the cardiology department at St. Vincent’s University Hospital in Dublin.
The primary care physicians looked for patients at least 40 years old with at least one identified cardiovascular risk factor whose B-type natriuretic peptide (BNP) level rose above 50 pg/mL on an annual screening test. They referred these patients to St. Vincent’s for an intensified testing and management program similar to "the disease management structure we’ve used for several years for patients with heart failure," said Dr. McDonald, a professor of cardiology at St. Vincent’s and director of the heart failure unit. The program included a cardiology review and regular follow-up, echocardiography with Doppler and other cardiovascular investigations as needed, and nurse coaching.
"Routine BNP screening is not recommended in current guidelines. Perhaps this finding is the first step to get guidelines committees to address the use of BNP for screening," commented Dr. Sanjay Kaul, director of the vascular physiology and thrombosis research laboratory at the Burns and Allen Research Institute at Cedars Sinai Medical Center in Los Angeles.
Among the 1,374 patients enrolled in the STOP-HF (Screening to Prevent Heart Failure) trial, annual BNP measurement found 498 (36%) with a BNP level that rose above 50 pg/mL in at least one annual test. This included 235 patients randomized to the control arm and 263 randomized to the intervention group. The overall age of patients in the study averaged 65 years, but the age of those with elevated BNP averaged closer to 70 years.
During average follow-up of just over 4 years, patients referred to the cardiology program had 25 cases (10%) of heart failure or asymptomatic left ventricular dysfunction, compared with 44 cases (19%) in the control arm, a 54% odds ratio reduction that was statistically significant for the study’s primary endpoint. For the entire study group of 1,374 randomized patients, participation in the group eligible for referred care cut the primary endpoint by a relative 41%, compared with the controls, a statistically significant difference.
A secondary efficacy analysis that tallied the combined rate of incident heart failure, arrhythmia, myocardial infarction, unstable angina, cerebrovascular events, peripheral thrombosis, or pulmonary embolism found 51 events (7%) in the entire intervention group compared with 71 events (10%) in the control group, a 46% odds rate reduction that was statistically significant.
A study limitation was the large percentage of patients in both arms either lost to follow-up, 10%; or who withdrew their consent to participate, another 16%. "It challenges interpretation of the results," commented Dr. Kaul.
But Dr. McDonald and his associates were convinced by their findings.
"We believe the results are conclusive enough to roll this out as a clinical program," he said in an interview. "We are now extending this to another region of Ireland, and we will try to get this disseminated nationally."
He also foresees additional refinements to the program, possibly identifying other risk markers that can compliment BNP and further focus intervention.
"We have shown benefit, but a question is the cost of getting that benefit. BNP is clearly a step up from where we were, but that doesn’t mean we are as good as we could make it."
Dr. McDonald said that he had no disclosures.
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