Effect of rheumatic process on myocardial performance in patients with mild to moderate rheumatic mitral regurgitation: a strain study

Background

Myocardial structural and functional changes may develop as a result of the inflammatory process in patients with rheumatic heart disease (RHD). How changes in myocardial function correlate to continuous rheumatic process in chronic RHD is not known.

Aim

To describe the long-term effect of rheumatic process on overall myocardial performance and its correlates to the maintenance of volume overload state induced by mitral regurgitation (MR).

Methods

We enrolled 210 consecutive patients (age: 43±9 years, 54% females) with primary MR. The study population was divided in two sub-groups according to aetiology of primary mitral disease, due to rheumatic or degenerative process with mild to moderate regurgitation. All patients underwent comprehensive transthoracic echocardiography for detection of myocardial dysfunction, including the assessment of LV and LA strain using 2D speckle tracking echocardiography. The MR was considered rheumatic in aetiology when the morphology of the valve satisfied the World Heart Federation criteria for the diagnosis of chronic RHD. Patients with ischemic heart disease, reduced LV ejection fraction or in arrhythmia at the time of echocardiography scan were excluded.

Results

The study included 70 patients with isolated degenerative MR and 70 patients with rheumatic MR and 70 sex matched healthy controls. Patients with rheumatic MR were younger and had a higher prevalence of atrial fibrillation, lower left ventricle (LV) global longitudinal strain (GLS), larger left atrium (LA) size and lower peak LA longitudinal strain (PALS) compared to patients with degenerative MR. Age, LV end-systolic volume and rheumatic aetiology were independently associated with impaired LVGLS. Whereas increased LV mass index and higher pulmonary hypertension were independently associated with significantly impaired PALS. However, there is no difference in the right ventricular dimensions and function indices between the two sub-groups.

Conclusions

The LV GLS and PALS seem to be the most sensitive echocardiographic parameters to assess changes in myocardial performance and to tackle overload state related to chronic RHD.

Figure: Comparisons of the values of LV end systolic volume (ESV), LV global longitudinal strain (GLS) and peak LA reservoir strain (PALS) in three groups.

Image: Example of echo-imaging in a patient with chronic RHD suffering from intermittent palpitation and dyspnoea. The images show thickening of anterior mitral leaflet with hockey-stick’ deformity and chordal thickening with mild mitral regurgitation, preserved LV ejection fraction and mildly impaired regional longitudinal strain of interventricular septum, mild tricuspid regurgitation, and mildly high systolic pulmonary artery pressure.For image description, please refer to the figure legend and surrounding text.For image description, please refer to the figure legend and surrounding text.