Impact of Mitral Annular Calcium and Mitral Stenosis on Outcomes After Transcatheter Aortic Valve Implantation

Transcatheter aortic valve implantation for combined aortic and mitral stenoses: Insights from the OCEAN-TAVI Registry

AIMS

Mitral stenosis (MS) occasionally coexists with aortic stenosis (AS). Limited data are available regarding the functional class and clinical outcomes of patients who undergo transcatheter aortic valve implantation (TAVI) for combined AS and MS. This study compared the clinical outcomes in patients with and without MS who underwent TAVI for severe AS and assessed the impact of mitral annulus calcification (MAC) severity, transmitral gradient (TMG) and mitral valve area (MVA) on outcomes in patients with combined AS and MS.

METHODS

We investigated patients in the OCEAN-TAVI registry who underwent TAVI. MS was defined as an MVA ≤ 1.5 cm2 or TMG ≥ 5 mmHg. The composite of all-cause death and admission for heart failure was compared between patients with and without MS. The impact of MAC, TMG and MVA on outcomes was assessed in patients with combined AS and MS.

RESULTS

We identified 106 patients with MS (MAC 84%; TMG 6.4 ± 2.6 mmHg; MVA 1.10 ± 0.31 cm2) and 6570 without MS as controls. The MS group was older (85 ± 5 vs. 84 ± 5 years, P = 0.033), more of women (85 vs. 67%, P < 0.01), and had a higher risk of surgery (the Society of Thoracic Surgeons Mortality Score 8.7 ± 5.1 vs. 7.6 ± 5.9, P = 0.047) than the controls. In the MS group, the New York Heart Association Functional Class was 3 or 4 in 56% of the patients at baseline and 6% at 1 year after TAVI. Thirty-day mortality (2.8% vs. 1.3%, P = 0.18) and early composite outcomes (17% vs. 15%, P = 0.56) were comparable between patients with and without MS. During a median follow-up of 2.1 years, the presence of MS was associated with a higher incidence of adverse events compared with controls (adjusted hazard ratio [HR] 1.84; 95% confidence interval [CI] 1.34-2.51, P < 0.01), even on propensity score matched analysis (adjusted HR 1.91; 95% CI 1.14-3.22, P < 0.01). Moderate or severe MAC contributed to increased risk of adverse events in patients with MS (adjusted HR 2.89; 95% CI 1.20-6.99, P = 0.018), but TMG and MVA did not.

CONCLUSIONS

In patients undergoing TAVI for severe AS, those with moderate or severe MS experienced worse outcomes after TAVI compared with those without MS. Patients with combined AS and MS sustained symptom improvement at 1-year post-TAVI. MAC severity was a useful predictor of adverse events compared with MS haemodynamics such as TMG and MVA in patients with combined AS and MS.

Outcomes of transcatheter aortic valve replacement in patients with mitral annular calcification and concomitant mitral valve dysfunction: A systematic review and meta-analysis

BACKGROUND

Calcific aortic stenosis is the principal indication for transcatheter aortic valve replacement (TAVR). Comorbid mitral annular calcification (MAC) is often present in patients undergoing TAVR. Limited data exist on the impact of MAC on TAVR outcomes. We conducted a systematic review and meta-analysis to explore the effects of MAC and concomitant mitral valve dysfunction (MVD) on TAVR outcomes.

METHODS

A comprehensive literature review was conducted using PubMed, Embase, Google Scholar, ClinicalTrials.gov, Scopus, and OVID for studies until March 20, 2023. Using the random-effects Mantel-Haenszel method, we calculated pooled risk ratios (RRs) and their corresponding 95 % confidence intervals (CIs) for all dichotomous variables.

RESULTS

Six studies comprising 5822 patients (2541 with MAC [severe MAC (>4 mm thickness) 583; non-severe MAC 1958; 400 with MVD; and 1071 without MVD], 3281 without MAC) met inclusion criteria. At 30 days and 1 year, no significant differences were observed between the overall MAC and no MAC groups in terms of mortality, stroke, and permanent pacemaker implantation. However, MAC with MVD was associated with a higher risk of all-cause mortality compared to MAC without MVD at 30 days (RR = 3.43, 95 % CI 2.04-5.76, P < 0.00001) and at 1 year (RR = 2.44, 95 % CI 1.85-3.20, P < 0.00001). Moreover, the risk of cardiovascular mortality was higher in patients with MAC and MVD compared to those with MAC alone (RR = 2.77, 95 % CI 1.89-4.06, P < 0.00001). Additionally, patients with severe MAC had a higher risk of major bleeding at 30 days compared to the non-severe MAC group (RR = 1.33, 95 % CI 1.04-1.69, P = 0.02).

CONCLUSION

TAVR appears to be safe in patients with non-severe MAC, but severe MAC is associated with a higher risk of major bleeding and concomitant MVD increases the mortality risk in patients undergoing TAVR.

Mitral Annular Calcification-Related Valvular Disease: A Challenging Entity

Mitral valve annular calcification-related valvular disease is increasingly common due to the rising prevalence of age-related mitral annular calcifications. Mitral annular calcification alters the structure and function of the mitral valve annulus, which in turn causes mitral valve regurgitation, stenosis, or both. As it frequently coexists with comorbid conditions and overlapping symptoms, mitral annular calcification-related valvular disease poses significant diagnostic and therapeutic challenges. For instance, left ventricular diastolic dysfunction hinders the assessment of mitral valvular disease. Detection of mitral annular calcifications and assessment of related mitral valve disease hinge on two-dimensional echocardiography. Comprehensive assessment of mitral annular calcifications and related mitral valve disease may require multidetector computed tomography and three-dimensional echocardiography. Invasive hemodynamic testing with exercise helps identify the cause of symptoms in patients with comorbid conditions, and transcatheter interventions have emerged as a viable therapeutic option for older patients. After an outline of the normal mitral annulus, we examine how mitral annular calcifications lead to mitral valve disease and how to accurately assess mitral regurgitation and stenosis. Lastly, we review surgical and transcatheter approaches to the management of mitral annular calcification-related mitral valve regurgitation, stenosis, or both.

Transcatheter Mitral Valve Replacement Using Transcatheter Aortic Valve or Dedicated Devices: Current Evidence and Future Prospects

Transcatheter mitral valve replacement (TMVR) is a novel and evolving field dedicated to addressing the therapeutic challenges posed by patients at high surgical risk with mitral valve disease. TMVR can be categorized into two distinct fields based on the type of device and its specific indications: TMVR with transcatheter aortic valves (TAV) and TMVR with dedicated devices. Similar to aortic stenosis, TMVR with TAV requires a rigid support structure to secure the valve in place. As a result, it is indicated for patients with failing bioprothesis or surgical rings or mitral valve disease associated with severe mitral annular calcification (MAC), which furnishes the necessary foundation for valve anchoring. While TMVR with TAV has shown promising outcomes in valve-in-valve procedures, its effectiveness remains more contentious in valve-in-ring or valve-in-MAC procedures. Conversely, TMVR with dedicated devices seeks to address native mitral regurgitation, whether accompanied by MAC or not, providing an alternative to Transcatheter Edge-to-Edge Repair (TEER) when TEER is not feasible or expected to yield unsatisfactory results. This emerging field is gradually surmounting technical challenges, including anchoring a valve in a non-calcified annulus and transitioning from the transapical route to the transeptal approach. Numerous devices are presently undergoing clinical trials. This review aims to furnish an overview of the supporting evidence for TMVR using TAV in each specific indication (valve-in-valve, valve-in-ring, valve-in-MAC). Subsequently, we will discuss the anticipated benefits of TMVR with dedicated devices over TEER, summarize the characteristics and clinical results of TMVR systems currently under investigation, and outline future prospects in this field.

Echocardiographic Mitral Annular Calcification is Associated With Atrial Fibrillation Recurrence After Catheter Ablation

There is a significant relation between mitral annular calcification (MAC) and the development of atrial fibrillation (AF) and major adverse cardiovascular events. However, the influence of MAC on the outcome of AF ablation remains unknown. The study cohort included 785 consecutive patients who underwent successful ablation. AF recurrence was monitored 3 months after ablation. Cox proportional hazards models were used to assess the association between MAC and AF recurrence. Kaplan-Meier analysis was performed to calculate the incidence of AF recurrence. Over a follow-up period of 16 ± 10 months, 190 patients (24.2%) experienced AF recurrence after ablation. MAC by echocardiography was identified in 42 patients (22%) with AF recurrence but only 60 without (10%, p <0.001). Patients with MAC were older (p <0.001), more often women (p <0.001), with a higher prevalence of hypertension (p <0.001) and diabetes mellitus (p<0.001), moderate/severe mitral regurgitation (p <0.001), larger left atrial dimension (p <0.001), and higher CHA₂DS₂-VASc score (p <0.001). Patients with MAC were more likely to develop AF recurrence than those without (36% vs 22%, respectively, p = 0.002). MAC was significantly associated with AF recurrence in the unadjusted analysis (hazard ratio 1.77, 95% confidence interval 1.26 to 2.58, p <0.001) and remained statistically significant after the multivariate adjustment (hazard ratio 1.48, 95% confidence interval 1.13 to 1.95, p = 0.001). In conclusion, echocardiographic MAC is significantly associated with an increased risk of AF recurrence after successful ablation, demonstrating an independent predictive value other than the established risk factors.

Mitral Valve Replacement for Mitral Stenosis Secondary to Massive Mitral Annular Calcium

Mitral annular calcium (MAC) may produce mitral stenosis (MS) if its quantity is massive. We define massive MAC as the presence of a huge quantity of calcium underlying the posterior mitral leaflet and extending across all or nearly all of the ventricular aspect of the anterior mitral leaflet. This report was prompted to emphasize the hazards of performing mitral valve replacement in patients with MS secondary to massive MAC. The clinical data and morphology of the operatively excised mitral valves from the 11 patients who had mitral valve replacement for MS secondary to massive MAC are described. Of the 11 patients, 6 died postoperatively, 5 of whom had 4+/4+ MAC. The high mortality in these patients suggests that the decision to perform mitral valve replacement needs to be carefully considered if the quantity of MAC is massive.