SAN DIEGO — Combining an electrocardiogram with serum N-terminal pro-B-type natriuretic peptide measurements is a simple, noninvasive way to diagnose pulmonary hypertension, results from an Austrian study suggest.
“Current pulmonary hypertension diagnosis guidelines say that ECG alone is not useful in the diagnosis of pulmonary hypertension. This is true,” Dr. Diana Bonderman said in an interview during a poster session at an international conference of the American Thoracic Society. “But if you combine ECG with NT-proBNP [N-terminal pro-B-type natriuretic peptide], it's going to be useful.”
The finding is important, she said, because the growing awareness of pulmonary hypertension PH, a high prevalence of postcapillary PH, and the inability to discern between pre- and postcapillary PH by transthoracic echocardiography (TTE) “have led to unnecessary right heart catheterizations.”
She and her associates prospectively analyzed data from 121 patients referred to the Medical University of Vienna between April 2007 and October 2008 for clinical and transthoracic echocardiographic suspicion of precapillary pulmonary hypertension (defined as having a systolic pulmonary artery pressure of at least 36 mm Hg). On admission, all patients underwent TTE, serum analysis including NT-proBNP, a 6-minute walk test, and blood gas analysis.
The patients were then assigned to one of two predicted diagnostic groups: precapillary PH (defined as right ventricular strain on ECG and/or serum NT-proBNP of greater than 80 pg/mL) or no precapillary PH (defined as no right ventricular strain on ECG and NT-proBNP of 80 pg/mL or less). Next, all patients underwent invasive hemodynamic measurements by right heart catheterization, and a final diagnosis was established.
The mean age of the patients was 62 years and 59% were female, reported Dr. Bonderman, a cardiologist at the Medical University of Vienna.
By right heart catheterization, 64 (53%) patients were diagnosed with precapillary PH. Precapillary PH was ruled out in 57 (47%) patients. By the diagnostic algorithm, 15 patients (12%) had been correctly allocated to the group without precapillary PH (true negatives). None of the allocations was a false negative.
“In the diagnostic pathway of PH, integration of the proposed algorithm subsequent to TTE may increase specificity from 0% to 19.3%, with a sensitivity of 100%,” the researchers wrote. “The incorporation of ECG and NT-proBNP into the workup of PH provides incremental diagnostic value and may significantly reduce the number of invasive assessments.”
The researchers had no conflicts to disclose.