Severe mitral annular calcification a ‘strong predictor’ of mortality after TAVR
medwireNews: Study results suggest that the presence of severe mitral annular calcification (MAC) is associated with increased all-cause and cardiovascular mortality risk following transcatheter aortic valve replacement (TAVR) among patients with calcified aortic stenosis (AS).
These findings suggest that severe MAC “should be included in future risk stratification models for TAVR,” say the study authors.
In a retrospective analysis, Raj Makkar (Cedars-Sinai Medical Center, Los Angeles, California, USA) and fellow researchers found that approximately half (49.3%) of 761 patients with calcified AS who underwent TAVR had MAC.
Severe MAC – defined as calcification in more than half of the mitral annulus circumference – was present in 9.5% of patients. Moderate MAC (involving between a third and half of the annulus) and mild MAC (involving less than a third of the annulus) occurred in 9.5% and 30.4% of patients, respectively.
Patients with and without MAC experienced similar risk for 30-day mortality and major complications, including myocardial infarction, respiratory failure, cardiogenic shock, and major bleeding. One-year mortality rates were 15.2% in patients with MAC versus 12.3% in patients without MAC, a nonsignificant difference.
However, compared with no MAC, severe MAC was associated with a significant increase in the risk for all-cause mortality, with a hazard ratio (HR) of 1.71.
In a multivariable survival analysis accounting for factors such as age, body mass index, and comorbidities, severe MAC was an “independent strong predictor” of all-cause and cardiovascular mortality following TAVR, with HRs for severe versus no MAC of 1.95 and 2.35, respectively.
Additionally, more patients with severe MAC than non-severe MAC required new permanent pacemaker implantation (PPI) after TAVR (25.5 vs 7.5%), and severe MAC was an independent predictor of new PPI requirement on multivariable analysis (odds ratio for severe vs no MAC=2.83).
The authors note in the European Heart Journalthat their single-center study had a “limited follow-up period,” at a mean of 21.5 months, and “[t]he sub-group of patients with severe MAC was relatively small and likely had high degree of confounding.”
And they conclude: “Future studies are needed to determine if patients with severe MAC and AS may benefit from earlier intervention and from lower threshold for PPI during follow-up after TAVR.”
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