Degenerative Mitral Stenosis: From Pathophysiology to Challenging Interventional Treatment

Balloon mitral valvuloplasty in low gradient severe rheumatic mitral stenosis: Immediate and short-term outcomes

Background

Efficacy of balloon mitral valvuloplasty (BMV) in low gradient severe rheumatic mitral stenosis (MS) is not very well defined. This study was undertaken to evaluate the outcomes of BMV in low gradient severe rheumatic MS.

Methods

Severe MS was defined as mitral valve area < 1.5 cm2. Low gradient was defined as mean diastolic trans-mitral gradient (MG) < 10 mmHg and low flow as stroke volume index < 35 ml/m2 on echocardiography. Sixty patients were divided into normal-flow/low-gradient (NFLG) (40) and low-flow/low-gradient (LFLG) (20) groups. Post-BMV parameters were recorded after 72 h and at the end of one year.

Results

Mean age was 36.2 ± 6.6 years in NFLG group and 40.6 ± 2.6 years in LFLG group (p < 0.01) and females were 75 % (n = 30) in NFLG group as compared to 60 % (n = 12) in LFLG group. Patients in the LFLG group had higher Wilkins score (p < 0.02) and prevalence of atrial fibrillation (n = 8, 40 %) as compared to NFLG group (n = 7, 17.5 %; p < 0.01). A greater decrease in MG was observed in NFLG group (p < 0.01), whereas increase in MVA was comparable in both the groups (p > 0.05). Ninety percent (n = 36) patients improved in NFLG group in comparison to 70 % (n = 14) in LFLG group (p < 0.01). At the end of one-year, symptomatic improvement persisted in all patients who became asymptomatic post-BMV.

Conclusion

Symptomatic improvement following BMV was better seen in NFLG group because of greater decrease in MG in comparison to LFLG group. Results of BMV were suboptimal in LFLG group because of higher sub-valvular obstruction, increased age and higher prevalence of AF.

Risk of stroke or systemic embolism in patients with degenerative mitral stenosis with or without atrial fibrillation: A cohort study

Background

Atrial fibrillation (AF) is associated with an increased risk of stroke and the combination of AF and mitral stenosis (MS) is associated with a higher risk. In developed nations, degenerative mitral stenosis (DMS) constitutes a sizeable proportion of patients with MS. Current international guidelines do not offer recommendations regarding anticoagulation in these patients. The objective of this study was to describe the incidence of stroke or systemic embolism in patients with DMS with or without prevalent AF.

Methods

A cohort study of DMS patients from 1997 to 2018, using data from the Danish health registries. The cohort was stratified based on AF prevalence and prior ischemic stroke. The primary outcome was a diagnosis of ischemic stroke or systemic embolism after 1 year of follow-up from time of DMS diagnosis.

Results

The study included 1162 patients with DMS, of which 421 had prevalent AF. The incidence rate of stroke or systemic embolism after 1 year of follow-up was highest in the DMS without AF group (7.58 vs. 6.63 per 100 person-years). In both groups, DMS without AF and DMS with AF, the incidence rate was highest in patients with prior thromboembolic events (29.61 vs. 5.15 and 19.53 vs. 5.15, respectively).

Conclusions

The incidence rate of stroke or systemic embolism was highest in DMS patients without AF. Current Danish guidelines recommend DMS patients should be treated with anticoagulation only with concurrent AF, yet our results call for additional research to establish if DMS patients without AF could benefit from stroke prevention therapy.

Left-Sided Degenerative Valvular Heart Disease in Type 1 and Type 2 Diabetes

BACKGROUND

The role of diabetes in the development of valvular heart disease, and, in particular, the relation with risk factor control, has not been extensively studied.

METHODS

We included 715 143 patients with diabetes registered in the Swedish National Diabetes Register and compared them with 2 732 333 matched controls randomly selected from the general population. First, trends were analyzed with incidence rates and Cox regression, which was also used to assess diabetes as a risk factor compared with controls, and, second, separately in patients with diabetes according to the presence of 5 risk factors.

RESULTS

The incidence of valvular outcomes is increasing among patients with diabetes and the general population. In type 2 diabetes, systolic blood pressure, body mass index, and renal function were associated with valvular lesions. Hazard ratios for patients with type 2 diabetes who had nearly all risk factors within target ranges, compared with controls, were as follows: aortic stenosis 1.34 (95% CI, 1.31-1.38), aortic regurgitation 0.67 (95% CI, 0.64-0.70), mitral stenosis 1.95 (95% CI, 1.76-2.20), and mitral regurgitation 0.82 (95% CI, 0.79-0.85). Hazard ratios for patients with type 1 diabetes and nearly optimal risk factor control were as follows: aortic stenosis 2.01 (95% CI, 1.58-2.56), aortic regurgitation 0.63 (95% CI, 0.43-0.94), and mitral stenosis 3.47 (95% CI, 1.37-8.84). Excess risk in patients with type 2 diabetes for stenotic lesions showed hazard ratios for aortic stenosis 1.62 (95% CI, 1.59-1.65), mitral stenosis 2.28 (95% CI, 2.08-2.50), and excess risk in patients with type 1 diabetes showed hazard ratios of 2.59 (95% CI, 2.21-3.05) and 11.43 (95% CI, 6.18-21.15), respectively. Risk for aortic and mitral regurgitation was lower in type 2 diabetes: 0.81 (95% CI, 0.78-0.84) and 0.95 (95% CI, 0.92-0.98), respectively.

CONCLUSIONS

Individuals with type 1 and 2 diabetes have greater risk for stenotic lesions, whereas risk for valvular regurgitation was lower in patients with type 2 diabetes. Patients with well-controlled cardiovascular risk factors continued to display higher risk for valvular stenosis, without a clear stepwise decrease in risk between various degrees of risk factor control.

Mitral Annular Calcification and Calcific Mitral Stenosis: Therapeutic Challenges and Considerations

PURPOSE OF REVIEW

Mitral annular calcification (MAC) and associated calcific mitral stenosis (MS) are frequent in the aging population, although optimal management remains debated and outcomes are poor. This article summarizes challenges in the diagnosis and therapy of calcific MS, the indications for valve intervention, procedural concerns, and emerging treatment options.

RECENT FINDINGS

Surgical mitral valve replacement is the procedure of choice in symptomatic patients at acceptable surgical risk, with transcatheter mitral valve replacement (TMVR) being evaluated in clinical trials as an alternative for patients at prohibitive surgical risk. Significant challenges exist with the currently available technology and outcomes have been suboptimal. Optimizing the patient-selection process by using multimodality imaging tools has proven to be essential. MAC and calcific MS is an increasingly prevalent, challenging issue with poor outcomes. While surgical valve replacement can be performed in patients with acceptable surgical risk, TMVR can be considered for patients at higher risk. Clinical trials are underway to optimize outcomes. Dedicated device designs and techniques to minimize risk of left ventricular outflow tract obstruction, paravalvular leakage, and device embolization are to be awaited.