The Prognostic Role of Global Longitudinal Strain in Severe Primary Mitral Regurgitation

MitraClip and left ventricular reverse remodelling: a strain imaging study

AIMS

The purpose of this study is to identify echocardiography predictors of clinical response and reverse left ventricular (LV) remodelling in patients with functional mitral regurgitation (FMR) treated with MitraClip.

METHOD AND RESULTS

We retrospectively analysed 86 high surgical risk patients with severe FMR; of those, 58 were implanted a MitraClip, and 28 received medical treatment and served as controls. At baseline and at 1-year follow-up, we performed clinical and echocardiography evaluation to assess global longitudinal strain (GLS) and myocardial work [global work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE)]. Mitral regurgitation was significantly reduced after MitraClip implantation (3.7 ± 0.4 vs. 1.7 ± 0.8, P < 0.001), and the procedure was associated with improvement in brain natriuretic peptide levels (980 ± 1027 vs. 420 ± 338 pg/mL, P < 0.001), New York Heart Association class status (3.2 ± 0.55 vs. 2.0 ± 0.6, P < 0.001), 6-min walking test (233 ± 154 vs. 286 ± 114 m, P = 0.01) at follow-up and reduction of left ventricle end-systolic (LVESV) and left ventricle end-diastolic volumes (LVEDV) (152 ± 68 vs. 136 ± 43 mL, P = 0.004 & 219 ± 74 vs. 193 ± 66 mL, P = 0.001, respectively). MitraClip procedure was associated with improvement of LV performance and significant increase of GWI (607 ± 282 vs. 650 ± 260 mmHg%, P = 0.045) and GCW (854 ± 288 vs. 949 ± 325 mmHg%, P < 0.001). Baseline ejection fraction (EF), GLS, GWI, GCW, and effective regurgitant orifice area were the variables that were associated with reduction of LVEDV 1 year after intervention (P < 0.05 for all) and baseline GCW of the LV was the only variable associated with reduction of LVESV (P = 0.002). Receiver operating characteristic curve analysis identified that a GLS cut-off value of -8.65% (AUC 0.815, P = 0.007) was associated with a 20% reduction of the LVEDV with a sensitivity and specificity of 72% and 70%, respectively, and that a GCW cut-off value of 846 mmHg% (AUC 0.759, P = 0.007) was associated with a 10% reduction of LVESV with sensitivity and specificity 79% and 74%, respectively.

CONCLUSIONS

Mitral valve repair with MitraClip has positive clinical and echocardiographic impact in patients with FMR 1 year after implantation. Preserved GLS and GCW values appear to be associated with LV reverse remodelling post intervention.

Predictors of Left Ventricular Dysfunction After Surgery for Degenerative Mitral Regurgitation

BACKGROUND

This study was performed to determine whether strain can supplement the ability of left ventricular (LV) ejection fraction (LVEF) to predict postoperative ventricular dysfunction in patients undergoing mitral valve surgery for degenerative mitral regurgitation (DMR).

METHODS

From 2004 to 2017, 520 patients with an LVEF of 60% or more underwent mitral valve surgery (98% repair) for DMR. All patients had preoperative, predischarge, and follow-up (mean, 5.0 ± 3.6 years) echocardiograms. Speckle tracking was performed in 119 of 520 patients (22.9%) to determine LV strain, right ventricular free-wall strain, and left atrial longitudinal strain. Multivariate logistic and Cox regression models were used in this subgroup to evaluate associations with early postoperative LV dysfunction and medium-term overall survival, respectively.

RESULTS

Median preoperative LVEF of the entire cohort was 65%. Based on predischarge echocardiogram, 449 patients (86.3%) maintained postoperative LVEF of 50% or greater. Seventy-one patients (13.7%) had a predischarge LVEF of less than 50%, 49 (9.4%) had a predischarge LVEF of 40% to 49%, and 22 (4.2% overall) had a predischarge LVEF of less than 40%. Abnormal preoperative LV, right ventricular, and left atrial strain measurements were significantly associated with the development of postoperative LV dysfunction, but preoperative hemodynamic and non-strain echo parameters did not vary enough in absolute values to be clinically useful as predictors of postoperative LV dysfunction.

CONCLUSIONS

Preoperative strain measurements in DMR patients were significantly associated with superior capabilities of detecting underlying LV dysfunction despite preserved preoperative LVEF. Strain analysis may serve as another marker for optimal timing of surgical intervention in DMR patients.

Pathophysiology and management of combined aortic and mitral regurgitation

The combination of aortic and mitral regurgitation is a typical example of a frequent yet understudied multiple valve disease scenario. The aetiology is often rheumatic or degenerative; less frequently it can be induced by drugs or radiation, or caused by infective endocarditis or congenital valvular lesions. Aortic regurgitation resulting in secondary mitral regurgitation is also not uncommon. There are limited data to guide the management of combined aortic and mitral regurgitation. Left ventricular dysfunction is frequent at initial presentation, and even more so postoperatively, suggesting that surgical management should not be delayed, particularly when symptoms occur or when there is evidence of even subtle left ventricular dysfunction. The decision to operate on one or both valves not only depends on the severity of each lesion, but also on several other factors, including age, co-morbidities and frailty, the increased operative risk of double valve surgery, the increased risk of long-term thrombotic and bleeding complications with multiple mechanical valves, the risk of leaving one valve unoperated and the probability of requiring redo surgery. The role of a multidisciplinary heart valve team is critical in this setting to optimize management and outcomes. The role of transcatheter approaches is currently limited, but technological advances will probably soon change the management paradigm.

Clinical application of echocardiographic-derived myocardial strain imaging in subclinical disease: a primer for cardiologists

PROPOSE OF REVIEW

To highlight the evidence to support the measurement of left ventricular (LV) global longitudinal strain (GLS) in the risk assessment and management of patients with valvular heart disease.

RECENT FINDINGS

Subclinical myocardial dysfunction that is characterized by impaired LV GLS is often present in patients with valvular disease. The addition of GLS to the LV systolic function assessment refines disease classification and improves both prognosis and management of valvular disease.

SUMMARY

The measurement of global systolic function is essential in risk assessment and management of all patients with valvular heart disease. Although LV ejection fraction remains the main parameter of systolic function, strain measurement has emerged as a promising systolic function marker. Strain describes deformation of the myocardium that occurs during the cardiac cycle in the longitudinal, circumferential, and radial planes. Of all the regional strain deformation measurements, evidence gathered over the last decade has shown that GLS improves detection of systolic dysfunction beyond LV ejection fraction and provides additional prognostic information.