ISSN 2996-8215
International Journal of Cardiology | Vol. 4, No. 4, April 2013 | pp. 25–32
DOI: 10.46882/2013/IJC/000049
Original Research Article
Prevalence and Prognostic Significance of Subclinical Left Ventricular Dysfunction in Severe Asymptomatic Primary Mitral Regurgitation
Elena R. Petrova¹, Dmitry V. Ivanov¹, Sergei N. Kozlov²
¹Department of Cardiology, Almazov National Medical Research Centre, St. Petersburg, Russia
²Division of Cardiovascular Surgery, Research Institute of Circulation Pathology, Novosibirsk, Russia
Abstract:
Timing surgical intervention in asymptomatic patients with severe primary mitral regurgitation (MR) and preserved left ventricular ejection fraction (LVEF greater than or equal to 60%) remains highly challenging. Subclinical myocardial dysfunction may develop before conventional threshold parameters are met. This study determined the prevalence of subclinical left ventricular dysfunction using global longitudinal strain (GLS) and evaluated its prognostic value for predicting post-operative heart failure development. We prospectively enrolled 115 asymptomatic patients with severe primary organic MR and an LVEF greater than or equal to 60%. Baseline standard and speckle-tracking echocardiography measured LVEF, left ventricular end-systolic diameter (LVESD), and GLS. Patients were tracked over a median of 38 months for the primary composite endpoint of heart failure symptom onset, new resting LVEF reduction less than 60%, or cardiac mortality. Subclinical LV dysfunction, defined as an absolute baseline GLS less than 18%, was identified in 38 patients (33.0%) despite a normal mean LVEF (64.2% ± 2.8%). The primary endpoint occurred in 28 patients (24.3%). Kaplan-Meier analysis revealed significantly lower event-free survival in patients with impaired GLS (log-rank p = 0.002). Multivariable Cox regression confirmed that an absolute GLS less than 18% was an independent predictor of long-term clinical worsening (hazard ratio: 2.12, 95% CI: 1.22–3.68, p = 0.005), outperforming conventional parameters like LVESD. Subclinical left ventricular dysfunction is prevalent in a third of asymptomatic patients with severe primary mitral regurgitation and independently predicts subsequent clinical decline.
Keywords: Primary mitral regurgitation, Echocardiography, Global longitudinal strain, Subclinical dysfunction, Prognosis, Mitral valve surgery
Received: January 08, 2013; Revised: February 20, 2013; Accepted: March 12, 2013; Published: April 18, 2013
Citation: International Journal of Cardiology, 2013, Vol. 4, No. 4, pp. 25–32, DOI: 10.46882/2013/IJC/000049