A clinical risk score of myocardial fibrosis predicts adverse outcomes in aortic stenosis

• Published in: European heart journal 2016-02, Vol.37 (8), p.713-723
• Main Authors: Chin, Calvin W L, Messika-Zeitoun, David, Shah, Anoop S V, Lefevre, Guillaume, Bailleul, Sophie, Yeung, Emily N W, Koo, Maria, Mirsadraee, Saeed, Mathieu, Tiffany, Semple, Scott I, Mills, Nicholas L, Vahanian, Alec, Newby, David E, Dweck, Marc R
• Format: Article
• Language: English
• Subjects: Aged; Aortic Valve Stenosis - mortality; Aortic Valve Stenosis - pathology; Clinical Research; Female; Fibrosis; Humans; Magnetic Resonance Angiography; Male; Myocardium - pathology; Prognosis; Risk Assessment - methods; Survival Analysis
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehv525

Midwall myocardial fibrosis on cardiovascular magnetic resonance (CMR) is a marker of early ventricular decompensation and adverse outcomes in aortic stenosis (AS). We aimed to develop and validate a novel clinical score using variables associated with midwall fibrosis. One hundred forty-seven patients (peak aortic velocity (Vmax) 3.9 [3.2,4.4] m/s) underwent CMR to determine midwall fibrosis (CMR cohort). Routine clinical variables that demonstrated significant association with midwall fibrosis were included in a multivariate logistic score. We validated the prognostic value of the score in two separate outcome cohorts of asymptomatic patients (internal: n = 127, follow-up 10.3 [5.7,11.2] years; external: n = 289, follow-up 2.6 [1.6,4.5] years). Primary outcome was a composite of AS-related events (cardiovascular death, heart failure, and new angina, dyspnoea, or syncope). The final score consisted of age, sex, Vmax, high-sensitivity troponin I concentration, and electrocardiographic strain pattern [c-statistic 0.85 (95% confidence interval 0.78-0.91), P < 0.001; Hosmer-Lemeshow χ(2) = 7.33, P = 0.50]. Patients in the outcome cohorts were classified according to the sensitivity and specificity of this score (both at 98%): low risk (probability score 57%). In the internal outcome cohort, AS-related event rates were >10-fold higher in high-risk patients compared with those at low risk (23.9 vs. 2.1 events/100 patient-years, respectively; log rank P < 0.001). Similar findings were observed in the external outcome cohort (31.6 vs. 4.6 events/100 patient-years, respectively; log rank P < 0.001). We propose a clinical score that predicts adverse outcomes in asymptomatic AS patients and potentially identifies high-risk patients who may benefit from early valve replacement.