Usefulness of the Mitral Regurgitation Severity Index to Assess the Severity of Chronic Mitral Regurgitation

• Published in: The American journal of cardiology Vol. 120; no. 2; pp. 304 - 308
• Main Authors: Afonso, Luis, MD, Shokr, Mohamed, MD, Akintoye, Emmanuel, MD, MPH, Briasoulis, Alexandros, MD, PhD, Alesh, Issa, MD, Alani, Anas, MD, Mahajan, Nitin, MD, MPH, Veeranna, Vikas, MD, Mostafa, Ashraf, MD, Zmily, Hammam, MD, Telila, Tesfaye, MD, Zalawadiya, Sandip, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 15-07-2017; Elsevier Limited
• Subjects: Blood Flow Velocity - physiology; Cardiovascular; Chronic Disease; Color; Confidence intervals; Confidence limits; Correlation coefficient; Correlation coefficients; Derivation; Diagnostic systems; Doppler; Echocardiography, Doppler, Color - methods; Echocardiography, Transesophageal - methods; Evaluation; Female; Flow velocity; Follow-Up Studies; Grading; Humans; Inflow; Integrals; Laboratories; Male; Middle Aged; Mitral Valve - diagnostic imaging; Mitral Valve Insufficiency - diagnosis; Mitral Valve Insufficiency - physiopathology; Patients; Predictive Value of Tests; Prostheses; Regurgitation; Reproducibility; Reproducibility of Results; Retrospective Studies; ROC Curve; Severity of Illness Index; Ultrasonic imaging; Ventricle; quantification index; time velocity integral; mitral regurgitation; Doppler
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/j.amjcard.2017.04.027

Abstract Existing metrics for grading mitral regurgitation (MR) are limited in terms of high inter-observer variability. We developed and evaluated a Doppler-based, semi-quantitative novel index (Mitral Regurgitation Severity Index, MRSI) of MR severity. In a total of 125 patients (70 in the derivation cohort and 55 in the validation cohort), MRSI was calculated as a ratio of time velocity integral of mitral inflow (Continuous wave Doppler –TVI MV) to the time velocity integral of the left ventricle outflow (Pulse wave Doppler-TVI LVOT). Inter-rater agreement for MRSI and predictive ability of the MRSI were then assessed. In the derivation cohort, MRSI differed significantly between patients with severe MR (2.6 ± 0.51) and mild-moderate (non-severe) MR (1.4±0.18) and a cut off of ≥1.8 was associated with optimal diagnostic accuracy. In the validation cohort, MRSI exhibited excellent agreement between a level II and a level III reader with a mean difference of -0.14 (95% confidence limit of agreement: -0.80 to 0.53), correlation coefficient of 0.88 (p<0.001), and 16% CV; and using the cut point of 1.8, it exhibited good inter-rater reproducibility with a kappa coefficient of 0.72 (p<0.001). In conclusion, MRSI appears to be a simple, quantitative, practical, color-independent metric to differentiate severe MR from non-severe MR