Correlation between Echocardiographic Diastolic Parameters and Invasive Measurements of Left Ventricular Filling Pressure in Patients with Takotsubo Cardiomyopathy

Abstract

The extent of diastolic dysfunction is of clinical importance in the risk stratification and management of patients with Takotsubo cardiomyopathy (TC). Standard echocardiographic indices of diastolic dysfunction have robust predictive ability in assorted disease states, but have not been validated in TC. The aim of this study was to compare Doppler metrics of diastolic function against catheterization-measured filling pressures in TC. Patients with TC who met inclusion and exclusion criteria were evaluated using echocardiography and catheterization performed within 24hours. Both left ventricular (LV) end-diastolic pressure and LV pre-A diastolic pressure were obtained from catheterization tracings. The echocardiographic parameters for diastolic function were extracted using the American Society of Echocardiography recommendations and a previously validated regression equation for mean left atrial pressure (mLAP). A total of 51 patients with TC were included. Patients were predominantly women (72.5%), with a mean age of 58±13years and a mean ejection fraction of 24±10 %. E/e' ratio (septal, average, and lateral) and calculated mLAP correlated positively with catheterization LV pre-A, with fair to moderate correlation (coefficient range, 0.38-0.44). The t-test mean difference between LV pre-A pressure and calculated mLAP was 0.77±7.34mm Hg (95% CI, ±14.68mm Hg) suggesting inconsistent measures. mLAP also exhibited poor diagnostic ability to discriminate elevated LV pre-A diastolic pressure, with an area under the receiver operating characteristic curve of 0.69 (95% CI, 0.50-0.88). Commonly used echocardiographic parameters for diastolic function demonstrated less-than-optimal correlation, with poor sensitivity and specificity, compared with invasively measured LV end-diastolic pressure or LV pre-A wave diastolic pressure in patients with TC. Precise characterization of LV filling pressure in patients with TC using contemporary noninvasive echocardiographic parameters appears challenging. Invasive measurements of filling pressure should remain the gold standard for optimal risk stratification and management of patients with TC.