The value and cost-effectiveness of screening for left ventricular (LV) dysfunction with echocardiography remains unclear, particularly since specific, evidence-based treatments are not available for the majority of patients with preserved systolic dysfunction, according to a study in the June issue of the Journal of Cardiac Failure.
In the study, Irene Betti, MD, from the Unità Operativa di Cardiologia, Ospedale S. Maria Annunziata, Azienda Sanitaria in Florence, Italy, and colleagues screened 1,012 primary care patients with hypertension and/or diabetes without signs or symptoms of heart failure or asymptomatic LV dysfunction, using measurements of NT-pro-BNP [N-terminal prohormone brain natriuretic peptide] and echocardiography. According to the researchers, diastolic dysfunction was found in 36 percent of the patients, and then categorized as mild in 327 patients and moderate-severe in 41. Systolic dysfunction was present in only 1.1 percent. NT-proBNP levels were 170 and 859 pg/mL respectively in diastolic and systolic dysfunction and 92 in normal subjects.
For the 5.1 percent of the subjects with moderate to severe diastolic dysfunction or systolic dysfunction, a NT-proBNP of less than 125 pg/ml had a negative predictive value (NPV) greater than 99 percent and a positive predictive value (PPV) of 33 percent in patients less than 67 years, the investigators reported. For older patients, NPV was 100 percent, but PPV was somewhat lower in women (23 percent) than in men (33 percent).
This study suggests that the evaluation of NT-proBNP in asymptomatic patients with type 2 diabetes or hypertension may lead to very early exclusion of LV dysfunction. As a perspective of this study, general practitioners could use NT-proBNP determination to rule out heart failure in these patients, a much more cost effective measure than the use of an echocardiographic one.
"This study demonstrates that low values of NT-proBNP usually exclude significant LV dysfunction, but elevated values are relatively non-specific, especially in a population where systolic dysfunction is rare," commented Barry M. Massie, MD, editor-in-chief of the Journal of Cardiac Failure.
The study was partially supported by an unrestricted grant from Roche Diagnostics.