Prognostic Signals From Moderate Valve Disease in Big Data: An Artefact of Digital Imaging and Communications in Medicine Structured Reporting?

Definition and Validation of Prognostic Phenotypes in Moderate Aortic Stenosis

BACKGROUND

Adverse outcomes from moderate aortic stenosis (AS) may be caused by progression to severe AS or by the effects of comorbidities. In the absence of randomized trial evidence favoring aortic valve replacement (AVR) in patients with moderate AS, phenotyping patients according to risk may assist decision making.

OBJECTIVES

This study sought to identify and validate clusters of moderate AS that may be used to guide patient management.

METHODS

Unsupervised clustering algorithms were applied to demographics, comorbidities, and echocardiographic parameters in a training data set in patients with moderate AS (n = 2,469). External validation was obtained by assigning the defined clusters to an independent group with moderate AS (n = 1,358). The primary outcome, a composite of cardiac death, heart failure hospitalization, or aortic valve (AV) intervention after 5 years, was assessed between clusters in both data sets.

RESULTS

Four distinct clusters-cardiovascular (CV)-comorbid, low-flow, calcified AV, and low-risk-with significant outcomes (log-rank P < 0.0001 in both data sets) were identified and replicated. The highest risk was in the CV-comorbid cluster (validation HR: 2.00 [95% CI: 1.54-2.59]; P < 0.001). The effect of AVR on cardiac death differed among the clusters. There was a significantly lower rate of outcomes after AVR in the calcified AV cluster (validation HR: 0.21 [95% CI: 0.08-0.57]; P = 0.002), but no significant effect on outcomes in the other 3 clusters. These analyses were limited by the low rate of AVR.

CONCLUSIONS

Moderate AS has several phenotypes, and multiple comorbidities are the key drivers of adverse outcomes in patients with moderate AS. Outcomes of patients with noncalcified moderate AS were not altered by AVR in these groups. Careful attention to subgroups of moderate AS may be important to define treatable risk.

Prognostic value of left ventricular and left atrial strain imaging in moderate to severe aortic stenosis: Insights from an Asian population

BACKGROUND

Data regarding the prognostic value of left atrial (LA) strain in aortic stenosis (AS) is scarce, especially in Asian population and moderate AS.

METHOD

Left ventricular global longitudinal strain (LVGLS), LA reservoir strain (LASr), conduit strain (LAScd), and contractile strain (LASct) were measured using automated speckle-tracking echocardiography in consecutive patients with moderate or severe AS. The primary endpoint was a composite of all-cause death (ACD) and major adverse cardiovascular events (MACE; myocardial infarction, syncope, and heart failure hospitalization).

RESULTS

Of 712 patients (mean age, 78 ± 12 years; 370 [52%] moderate AS; 342 [48%] severe AS), average LV ejection fraction (LVEF) was 68 with SD of 12%. At a median follow-up of 18 months (interquartile range, 11-26 months), the primary endpoint occurred in 93 patients (60 deaths and 35 MACEs) and 221 patients underwent surgical or transcatheter aortic valve replacement (AVR). In the entire cohort, separate multivariable models adjusted for age, Charlson index, symptomatic status, time-dependent AVR, AS-severity, LA volume index and LVEF demonstrated that only LASr was associated with MACE+ACD (Hazard ratio, 0.97; P = 0.014). Subgroup analysis for MACE+ACD demonstrated consistent prognostication for LASr in moderate and severe AS; LVGLS was prognostic only in severe AS (all P ≤ 0.023). The optimal MACE+ACD cutoff for LASr from spline curves was 21.3%. Adjusted Kaplan-Meier curves demonstrated better event-free survival in patients with LASr >21.3% versus those with LASr ≤21.3% (P = 0.04).

CONCLUSIONS

In both moderate and severe AS, only LASr robustly predicted outcomes; thus, including LASr in the AS staging algorithm should be considered.