MR Product as a Novel Diagnostic Indicator for Chronic Secondary Mitral Regurgitation.

Background Chronic secondary mitral regurgitation (SMR) is a common form of valvular heart disease. Its diagnosis through echocardiography is challenging and dependent on subjective interpretations. The subjective error to diagnose SMR can be reduced by developing accurate predictive quantitative parameters that support echocardiographic interpretations and clinical manifestations. The present study aims to develop a new diagnostic indicator for chronic SMR. The new indicator called MR product is the product of left atrial diameter (LAD) and left ventricular internal dimension at end-systole (LVIDs). Materials and Methods An analytical, case-control study was conducted from transthoracic echocardiography (TTE) reports of 720 patients performed according to the guidelines of the American Society of Echocardiography. The LAD and LVIDs were measured using the standard M Mode TTE. Out of the 720 patients who underwent TTE, 300 patients were diagnosed with chronic SMR by experienced clinicians. Only 115 of those 300 patients met the inclusion criteria for chronic SMR.  Results The MR product was significantly associated with chronic SMR (rho = 0.83) and predicted it with an odds ratio of 1.014 (p < 0.001). The MR product was able to diagnose SMR with a sensitivity of 94.8% and a specificity of 92.2%, respectively, for a cut off value of 1,045 mm. Conclusion A new parameter called MR product (LAD multiplied with LVIDs) has very high sensitivity and specificity for SMR. Therefore, it can aid in establishing its diagnosis, along with other diagnostic modalities. The new parameter may also potentially increase the diagnostic accuracy of the disease.