Clinical and prognostic implications of cardiopulmonary exercise stress echocardiography in asymptomatic degenerative mitral regurgitation

Abstract

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): The Saudi Arabian Cultural Bureau. Background Current guidelines recommend intervention in severe degenerative mitral regurgitation (MR) in symptomatic patients or asymptomatic patients with left ventricular dilatation or dysfunction. The insidious onset of symptoms may mean patients do not report symptoms. The role of systematic exercise testing for symptoms in MR is not clearly defined. Methods 97 patients with moderate to severe, asymptomatic MR underwent exercise echocardiography combined with cardiopulmonary exercise testing. Predictors of exercise-induced dyspnoea, symptom-free survival and mitral valve intervention were identified. Results 18 (19%) patients developed limiting dyspnoea on exercise. Spontaneous symptom free survival at 24 months was significantly higher in those without exercise-induced symptoms compared to those with exercise-induced symptoms, p <0.0001. The only independent predictors of spontaneous symptoms at 2 years were effective regurgitant orifice area (odds ratio 27.45 (95% CI 1.43 – 528.40), p = 0.03) and exercise-induced symptoms (odds ratio 11.56 (95% CI 1.71 – 78.09), p = 0.01). The only independent predictor of surgery was indexed left ventricular systolic volumes (Odds ratio 1.17 (95% CI 1.04 – 1.30), p = 0.006). Where only patients undergoing surgery due to symptoms were included, the only independent predictor was exercise-induced symptoms (Odds ratio 13.94 (95% CI 1.39 – 140.27), p = 0.025). Conclusion In patients with primary asymptomatic degenerative MR, one fifth develop symptoms on exercise. This predicts subsequent development of spontaneous symptoms and mitral valve intervention due to symptoms.