Left Ventricle Myocardial Performance Index Derived Either By Conventional Method or Mitral Annulus Tissue-Doppler: A Comparison Study in Healthy Subjects and Subjects with Heart Failure

Abstract

The aims of this study were to investigate the clinical agreement between myocardial performance index (MPI) measured conventionally and by pulsed-wave tissue Doppler (PW-TD) of the mitral annulus, and to test whether PW-TD MPI can accurately differentiate between healthy subjects and patients affected by congestive heart failure (CHF) with mild to moderate reduction of systolic function. Calculation of MPI using PW-TD may have advantages over conventional left ventricle inflow/outflow tract pulsed-wave Doppler (PWD) method; for example, all of the data needed for PW-TD MPI calculation can be derived from one single cardiac cycle, whereas with PWD at least two different cycles are needed. Thus, heart rate variability does not interfere with PW-TD MPI. In group A, we included 70 healthy adults with normal left ventricular ejection fraction and normal diastole, whereas for group B we studied 50 patients with CHF and left ventricular ejection fraction between 35% and 45%. MPI measured with PWD was statistically different (P < .0001) from MPI measured with PW-TD both in group A (0.33 +/- 0.09 vs 0.42 +/- 0.09) and group B (0.69 +/- 0.15 vs 0.79 +/- 0.12). Nonetheless, clinical agreement existed between the two methods in the single subject. Receiver operating characteristic curves showed very high accuracy for both methods to discriminate patients with CHF from healthy subjects; the optimal cutoff point was different and specific to each method: 0.50 for the conventional method and 0.60 for the PW-TD method. We found clinical agreement between MPI measured in the same subject with the conventional PWD method and with PW-TD. Both methods had similarly high diagnostic accuracy for CHF, but this study supports the use of a higher MPI cut-point for best diagnostic accuracy when using the new PW-TD method. We performed a study in healthy adults and in patients with congestive heart failure to investigate the clinical agreement between MPI measured conventionally and by PW-TD of the mitral annulus. We found mild agreement between MPI measured by the conventional method and by PW-TD. Both methods had high diagnostic accuracy for CHF. PW-TD method requires a higher MPI cut-point for best diagnostic accuracy.