Mitral annular calcification in patients undergoing aortic valve replacement for aortic valve stenosis

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.

A Systematic Review and Meta-Analysis of Prevalence, Characteristics, and Impact of Mitral Annular Calcification on Outcomes After Transcatheter Aortic Valve Implantation

There is a paucity of data on the prognostic impact of mitral annular calcification (MAC) in patients who underwent transcatheter aortic valve implantation (TAVI) with conflicting results being reported by the studies that are published. Therefore, we performed a meta-analysis to assess the short-term and long-term outcomes of MAC in patients after TAVI. Of 25,407 studies identified after the initial database search, 4 observational studies comprising 2,620 patients (2,030 patients in the nonsevere MAC arm and 590 patients in the severe MAC arm) were included in the final analysis. Compared with patients with nonsevere MAC, the severe MAC group was associated with significantly higher incidences of overall bleeding (0.75 [0.57 to 0.98], p = 0.03, I² = 0%) at 30 days. However, no significant difference was observed between the 2 groups for the rest of the 30-day outcomes: all-cause mortality (0.79 [0.42 to 1.48], p = 0.46, I² = 9%), myocardial infarction (1.62 [0.37 to 7.04], p = 0.52, I² = 0%), cerebrovascular accident or stroke (1.22 [0.53 to 2.83], p = 0.64, I² = 0%), acute kidney injury (1.48 [0.64 to 3.42], p = 0.35, I² = 0%), and pacemaker implantation (0.70 [0.39 to 1.25], p = 0.23, I² = 68%). Similarly, follow-up outcomes also showed no significant difference between the 2 groups: all-cause mortality (0.69 [0.46 to 1.03], p = 0.07, I² = 44%), cardiovascular mortality (0.52 [0.24 to 1.13], p = 0.10, I² = 70%) and stroke (0.83 [0.41 to 1.69], p = 0.61, I² = 22%). The sensitivity analysis, however, demonstrated significant results for all-cause mortality (0.57 [0.39 to 0.84], p = 0.005, I² = 7%) by removing the study by Okuno et al⁵ and cardiovascular mortality (0.41 [0.21 to 0.82], p = 0.01, I² = 66%) by removing the study by Lak et al.⁷ In conclusion, our meta-analysis corroborates the notion that isolated MAC is not an independent predictor of long-term mortality after TAVI and determines severe MAC to be a predictor of mortality at follow-up because of the higher incidence of mitral valve dysfunction associated with it.

Mitral annular calcification and valvular dysfunction: multimodality imaging evaluation, grading, and management

Mitral annular calcification (MAC) refers to calcium deposition in the fibrous skeleton of the mitral valve. It has many cardiovascular associations, including mitral valve dysfunction, elevated cardiovascular risk, arrhythmias, and endocarditis. Echocardiography conventionally is the first-line imaging modality for anatomic assessment, and evaluation of mitral valve function. Cardiac computed tomography (CT) has demonstrated importance as an imaging modality for the evaluation and planning of related procedures. It also holds promise in quantitative grading of MAC. Currently, there is no universally accepted definition or classification system of MAC severity. We review the multimodality imaging evaluation of MAC and associated valvular dysfunction and propose a novel classification system based on qualitative and quantitative measurements derived from echocardiography and cardiac CT.

Presence of mitral stenosis is a risk factor of new development of acute decompensated heart failure early after transcatheter aortic valve implantation

AIMS

Acute decompensated heart failure (ADHF) can occur early after transcatheter aortic valve implantation (TAVI), but the risk factors or mechanisms associated with it have not been fully determined. This hypothesis-generating study aimed to investigate the clinical indices associated with the development of ADHF within 72 hours after TAVI and to improve procedural approaches for TAVI.

METHOD AND RESULTS

In this single-centre hypothesis generating prospective observational study, we enrolled 156 consecutive patients with severe aortic stenosis who underwent TAVI between January 2016 and February 2018 at our institution. We set the primary endpoint as the new development of ADHF within 72 hours after TAVI, and clinical indices associated with it were evaluated using a multivariable logistic model. The median age of the patients was 83 (quartile range 80-86) years, 48 (30.8%) were men and the median Society of Thoracic Surgery-Predicted Risk of Mortality was 7.1 (range 5.2-10.4). Mitral stenosis (MS), defined as mean transmitral valve pressure gradient ≥5 mm Hg, was present in 15 (9.6%) patients. After TAVI, the invasive mean transaortic valve pressure gradient (mAVPG) decreased from 48 (36-66) to 7 (5-11) mm Hg, and 12 (7.7%) patients developed ADHF within 72 hours after TAVI. Multivariable logistic regression analysis showed that MS (adjusted OR, 14.227; 95% CI 2.654 to 86.698; p=0.002) and greater decreases in mAVPG (1.038; 1.003 to 1.080; p=0.044) were associated with ADHF.

CONCLUSIONS

MS and drastic improvement of mAVPG were associated with new development of ADHF within 72 hours after TAVI.

Mitral annular calcification in the elderly - Quantitative assessment

PURPOSE

To determine the reliability of subjective and objective quantification of mitral annular calcification (MAC) in elderly patients with severe aortic stenosis, to define quantitative sex- and age-related reference values of MAC, and to correlate quantitative MAC with mitral valve disease.

METHODS

In this retrospective, IRB-approved study, we included 559 patients (268 females, median age 81 years, inter-quartile range 77-85 years) with severe aortic stenosis undergoing CT. Four independent readers performed subjective MAC categorization as follows: no, mild, moderate, and severe MAC. Two independent readers performed quantitative evaluation of MAC using the Agatston score method (Agatston_MAC). Mitral valve disease was determined by echocardiography.

RESULTS

Subjective MAC categorization showed high inter-reader agreement for no (k ​= ​0.88) and severe MAC (k ​= ​0.75), whereas agreement for moderate (k ​= ​0.59) and mild (k ​= ​0.45) MAC was moderate. Intra-reader agreement for subjective MAC categorization was substantial (k ​= ​0.69 and 0.62). Inter- and intra-reader agreement for Agatston_MAC were excellent (ICC ​= ​0.998 and 0.999, respectively), with minor inconsistencies in MAC involving the left ventricular outflow tract/aortic valve. There were significantly more women than men with MAC (n ​= ​227, 85% versus n ​= ​209, 72%; p ​< ​0.001), with a significantly higher Agatston_MAC (median 597, range 81-2055 versus median 244; range 0-1565; p ​< ​0.001), particularly in patients ≥85 years of age. Agatston_MAC showed an area-under-the-curve of 0.84 to diagnose mitral stenosis, whereas there was no association of Agatston_MAC with mitral regurgitation (p ​> ​0.05).

CONCLUSIONS

Our study in elderly patients with severe aortic stenosis shows that quantitative MAC scoring is more reliable than subjective MAC assessment. Women show higher Agatston_MAC scores than men, particularly in the elderly population. Agatston_MAC shows high accuracy to diagnose mitral stenosis.

Does isolated mitral annular calcification in the absence of mitral valve disease affect clinical outcomes after transcatheter aortic valve replacement?

Aims 

Mitral annular calcification (MAC) has been associated with adverse outcomes in patients undergoing transcatheter aortic valve replacement (TAVR) but has been investigated in isolation of co-existent mitral regurgitation or mitral stenosis, which may represent important confounders. This study sought to investigate the effect of MAC with and without concomitant mitral valve disease (MVD) on clinical outcomes in patients treated with TAVR.

Methods and results 

Computed tomography (CT) and echocardiographic data in consecutive TAVR patients enrolled into a prospective registry were categorized according to presence or absence of severe MAC and significant MVD, respectively. A total of 967 patients with adequate CT and echocardiography data were included between 2007 and 2017. Severe MAC was found in 172 patients (17.8%) and associated with MVD in 87 patients (50.6%). Compared to TAVR patients without severe MAC or MVD, all-cause mortality at 1 year was significantly increased among patients with severe MAC in combination with MVD [adjusted hazard ratio (HRadj): 1.97, 95% confidence interval (CI): 1.12–3.44, P = 0.018] and patients with isolated MVD (HRadj: 2.33, 95% CI: 1.56–3.47, P &lt; 0.001), but not in patients with isolated severe MAC in the absence of MVD (HRadj: 0.52, 95% CI: 0.21–1.33, P = 0.173).

Conclusion 

We found no effect of isolated MAC on clinical outcomes following TAVR in patients with preserved mitral valve function. Patients with MVD had an increased risk of death at 1 year irrespective of MAC.

Impact of High Baseline Left Ventricular Filling Pressure on Transcatheter Aortic Valve Replacement Outcomes in Patients with Significant Mitral Annular Calcification

BACKGROUND

Left ventricular filling pressure (LVFP) has been demonstrated to be a major predictor of poor cardiovascular outcomes. However, estimation of LVFP in patients with aortic stenosis is limited by the high prevalence of significant mitral annular calcification. The aim of this study was to investigate the effect of transcatheter aortic valve replacement on LVFP and the relationship of LVFP to mortality and hospitalization.

METHODS

This was a single-center, retrospective study of 140 consecutive patients in sinus rhythm with significant mitral annular calcification who underwent transcatheter aortic valve replacement for severe aortic stenosis from May 2011 to June 2015. Mean follow-up duration was 3.06 ± 1.48 years (minimum, 2.4 years; maximum, 6.5 years). Diastolic function was assessed using recently proposed criteria for those with significant mitral annular calcification. High LVFP was defined as a mitral E/A ratio > 1.8 or a ratio of 0.8 to 1.8 and isovolumic relaxation time < 80 msec.

RESULTS

At baseline, the proportion of patients with high LVFP was 40.7%, similar to 1 month (39.7%) (P = .86). However, the proportion of patients with high LVFP was significantly decreased at 1 year compared with those at baseline (26.9% vs 40.7%, P = .02). Multivariate analysis showed that high LVFP at baseline significantly increased risk for all-cause mortality compared with patients with normal LVFP (hazard ratio, 2.84; 95% confidence interval, 1.33-6.05; P = .007).

CONCLUSIONS

High baseline LVFP was associated with a significantly increased all-cause mortality, and LVFP does not improve in the short term but only at 1 year after transcatheter aortic valve replacement.

Concomitant mitral annular calcification and severe aortic stenosis: prevalence, characteristics and outcome following transcatheter aortic valve replacement

Aims

Calcified aortic stenosis (AS) and mitral annular calcification (MAC) have certain similar etiology and pathophysiological mechanisms. MAC is frequently encountered in pre-procedural computed tomography (CT) imaging of patients that undergo transcatheter aortic valve replacement (TAVR), but its prognostic implications for these patients have not been thoroughly investigated. This study sought to evaluate the prevalence of MAC among patients with severe AS and to assess the clinical implications of MAC on these patients during and following TAVR.

Methods and results

Consecutive patients that underwent TAVR were compared according to the existence of MAC and its severity in pre-TAVR CT scans. From the entire cohort of 761 patients, 49.3% had MAC, and 50.7% did not have MAC. Mild MAC was present in 231 patients (30.4%), moderate MAC in 72 patients (9.5%), and severe MAC in 72 patients (9.5%). Thirty-day mortality and major complications were similar between patients with and without MAC. In a multivariable survival analysis, severe MAC was found to be an independent strong predictor of overall mortality following TAVR (all-cause mortality: hazards ratio [HR] 1.95, 95% confidence interval [CI] 1.24-3.07, P = 0.004; cardiovascular mortality: HR 2.35, 95% CI 1.19-4.66; P = 0.01). Severe MAC was also found to be an independent strong predictor of new permanent pacemaker implantation (PPI) after TAVR (OR 2.83, 95% CI 1.08-7.47; P = 0.03).

Conclusion

Half of the patients with severe AS evaluated for TAVR were found to have MAC. Severe MAC is associated with increased all-cause and cardiovascular mortality and with conduction abnormalities following TAVR and should be included in future risk stratification models for TAVR.

Relation of an Echocardiographic-Based Cardiac Calcium Score to Mitral Stenosis Severity and Coronary Artery Disease in Patients with Severe Aortic Stenosis

Patients with calcific aortic stenosis (AS) often have diffuse cardiac calcification involving the mitral valve apparatus and coronary arteries. We examined the association between global cardiac calcification quantified by a previously validated echocardiographic calcium score (eCS) with the severity of mitral stenosis (MS) and coronary artery disease (CAD) in patients with a clinical diagnosis of severe calcific AS. In this sample of 147 patients (mean age 81 ± 9 years, 50% male), 81 patients (55%) were determined by echocardiography to have some degree of MS. Higher mean eCS was observed in patients with more severe MS (r = 0.54, p < 0.0001). Higher eCS was also inversely associated with mitral valve area (r = -0.31, p = 0.001) and positively associated with mitral valve mean pressure gradient (r = 0.46, p < 0.0001) and mitral valve peak flow velocity (r = 0.55, p < 0.0001). The area under the receiver operating characteristic curve for using eCS to predict the presence of MS was 0.76. An eCS ≥ 8 predicted MS with a sensitivity of 68%, specificity of 76%, positive predictive value of 77%, and negative predictive value of 66%. High eCS, relative to low eCS, was associated with 2.70 times the adjusted odds of CAD (odds ratio = 2.70, 95% confidence interval 1.02 to 7.17). In conclusion, global cardiac calcification is associated with MS and CAD in patients with severe calcific AS, and eCS shows ability to predict the presence of MS. This study suggests that a simple eCS may be used as part of a risk-stratification tool in patients with severe calcific aortic valve stenosis.

Impact of Mitral Annular Calcium on Outcomes after Transcatheter Aortic Valve Implantation

A high prevalence of mitral annular calcium (MAC) is expected in patients undergoing transcatheter aortic valve implantation (TAVI); however, data regarding the prevalence of MAC and impact on risk of cardiovascular events are lacking. To determine the prevalence of MAC and its association with clinical outcomes in patients undergoing TAVI, we retrospectively analyzed 424 patients who underwent transfemoral TAVI from 2007 to 2015 and whose preoperative computed tomography images were available for assessment of MAC. Severe circumferential MAC (SC-MAC) was defined as calcification involving at least the whole posterior annulus alone or with the attachment of the anterior leaflet. Clinical outcomes were examined according to Valve Academic Research Consortium-2 criteria up to 2 years. SC-MAC was found in 17.7% of patients. Patients with SC-MAC were more likely to be female, with a higher prevalence of atrial fibrillation and peripheral artery disease. There were no differences between the groups regarding age, functional class, prevalence of diabetes, kidney disease, and operative risk. Female gender and peripheral artery disease were independent predictors of SC-MAC. SC-MAC did not appear to be associated with periprocedural and 30-day outcomes. At 2 years' follow-up, patients with SC-MAC had significantly higher cardiovascular and all-cause mortality rates. SC-MAC was an independent predictor of cardiovascular mortality during follow-up. In conclusion, SC-MAC is a frequent finding in the TAVI population and appears to be an independent predictor of cardiovascular mortality at 2 years' follow-up.

Echocardiographically derived effective valve opening area in mitral prostheses: a comparative analysis of various calculations using continuity equation and pressure half time method

Detection of dysfunctional mitral valve prostheses (MP) remains complex even though being optimized by considering echocardiographically derived prosthetic effective orifice area (VA). The purpose was to compare VA in MP, calculated by the continuity equation (CE) using peak velocities (CEVpeak), mean velocities (CEVmean), velocity-time integrals (CEVTI) and the pressure half time method using 220 ms as constant first (PHT220) as well as optimized constants. In 267 consecutive patients with normally functioning MP, we investigated VA within the first postoperative month. With increasing prosthetic sizes, mean VA values also increase in all calculations. The statistical curves demonstrate no significant difference in graphical steepness but show different levels. Comparison of mean VA showed the known systematic higher values of PHT220 and significantly decreased results when using CEVTI. This systematic difference between mean VA applying PHT220 versus CEVTI is approximately 1.0 cm(2) for all prosthetic sizes. Calculations via CEVpeak were close to the results of CEVTI. CEVmean produced values, which graphically correspond to the PHT220 curve. Only PHT220 detected the constructional equal prosthetic inner ring width between 29 and 31 mm. To compensate the systematic difference between CEVTI and PHT220, an optimized constant of 140 ms was calculated to be applied in PHT (PHT140). VA is a robust and, therefore, preferable parameter for investigating MP. If needed, both CE and PHT are applicable with a systematical difference between CEVTI and PHT220. An optimized constant of 140 ms (PHT140) should be applied when calculating VA of mitral valve prostheses via PHT.