N-terminal-pro-brain natriuretic peptide, a surrogate biomarker of combined clinical and hemodynamic outcomes following percutaneous transvenous mitral commissurotomy

Aim: To examine the relationship between plasma levels of N-terminal-proB type natriuretic peptide [NT-proBNP] and various echocardiographic and hemodynamic parameters in patients with mitral stenosis undergoing percutaneous transvenous mitral commissurotomy [PTMC]

Materials and methods: The study population consisted of 100 patients with rheumatic mitral stenosis who underwent PTMC. NT-proBNP levels in these patients were measured before PTMC and 48 hours after PTMC. These levels were then correlated with various echocardiographic and hemodynamic parameters measured before and after PTMC

Results: Eighty-one percent of the study population were women, and the most common presenting symptom was dyspnea which was present in 94% of the patients. Dyspnea New York Heart Association class correlated significantly with baseline NT-proBNP levels [r = 0.63; p < 0.01]. The plasma NT-proBNP levels in these patients increased as echocardiogram signs of left atrial enlargement and right ventricular hypertrophy developed [r = 0.59, p < 0.01]. Patients in atrial fibrillation had significantly higher NT-proBNP levels than patients in sinus rhythm. Baseline NT-proBNP levels correlated significantly with left atrial volume [r = 0.38; p < 0.01], left atrial volume index [r = 0.45; p < 0.01], systolic pulmonary artery pressures [r = 0.42; p < 0.01], and mean pulmonary artery pressures [r = 0.41; p < 0.01]. All patients who underwent successful PTMC showed a significant decrease in NT-proBNP [decreased from a mean 763.8 pg/mL to 348.6 pg/mL] along with a significant improvement in all echocardiographic and hemodynamic parameters [p < 0.01]. The percent change in NT-proBNP correlated significantly with the percent improvement noted with left atrial volume [r = 0.39; p < 0.01], left atrial volume index [r = 0.41; p < 0.01], systolic [r = 0.32, p < 0.01], and mean pulmonary artery pressures [r = 0.31, p < 0.01]

Conclusions: The decrease in NT-proBNP levels following PTMC reflects an improvement in clinical and hemodynamic status; hence, it is reasonable to suggest that NT-proBNP is helpful in evaluating the response to PTMC

Impact of metabolic syndrome on global left ventricular function: As evaluated by the myocardial performance index

Background: Metabolic syndrome is associated with the development of diabetes mellitus and cardiovascular disease

The impact of metabolic syndrome on the progression of atherosclerosis has been well documented

This study was designed to evaluate the impact of metabolic syndrome on global left ventricular function by using left ventricular myocardial performance index [LVMPI]

Methods: The diagnosis of metabolic syndrome was made as per the criteria of the International Diabetes Federation. Echocardiography was performed with a Philips IE33 machine using a 1-5 MHz transthoracic probe

LVMPI was calculated by adding isovolumic contraction time with isovolumic relaxation time and dividing it by ejection time

Results: The mean LVMPI value in metabolic syndrome was 0.64 +/- 0.09, while that in controls was 0.48 +/-0.06 [p < 0.001]

Metabolic syndrome was seen to have more significant influence on LVMPI

Conclusions: Metabolic syndrome is a strong predictor of sub-clinical myocardial dysfunction in subjects free of clinically apparent heart disease