Clinical Risk Score to Predict Pathogenic Genotypes in Patients With Dilated Cardiomyopathy
Luis Escobar-López, Juan Pablo Ochoa, Ana Royuela, Job A.J. Verdonschot, Matteo Dal Ferro, María Ángeles Espinosa, María Sabater‐Molina, María Gallego‐Delgado, José M. Larrañaga‐Moreira, José Manuel García‐Pinilla, María Teresa Basurte-Elorz, José F. Rodríguez‐Palomares, Vicente Climent, Francisco Bermúdez-Jiménez, María Victoria Mogollón‐Jiménez, Javier López, María Luisa Peña‐Peña, Ana García‐Álvarez, Bernardo López-Abel, Tomás Ripoll‐Vera, Julián Palomino-Doza, Antoni Bayés‐Genís, Ramón Brugada, Uxua Idiazabal, Jesús G. Mirelis, Fernándo Domínguez, Michiel T.H.M. Henkens, Ingrid P.C. Krapels, Han G. Brunner, Alessia Paldino, Denise Zaffalon, Luisa Mestroni, Gianfranco Sinagra, Stéphane Heymans, Marco Merlo, Pablo García‐Pavía
Abstract
BACKGROUND: Although genotyping allows family screening and influences risk-stratification in patients with nonischemic dilated cardiomyopathy (DCM) or isolated left ventricular systolic dysfunction (LVSD), its result is negative in a significant number of patients, limiting its widespread adoption. OBJECTIVES: This study sought to develop and externally validate a score that predicts the probability for a positive genetic test result (G+) in DCM/LVSD. METHODS: Clinical, electrocardiogram, and echocardiographic variables were collected in 1,015 genotyped patients from Spain with DCM/LVSD. Multivariable logistic regression analysis was used to identify variables independently predicting G+, which were summed to create the Madrid Genotype Score. The external validation sample comprised 1,097 genotyped patients from the Maastricht and Trieste registries. RESULTS: A G+ result was found in 377 (37%) and 289 (26%) patients from the derivation and validation cohorts, respectively. Independent predictors of a G+ result in the derivation cohort were: family history of DCM (OR: 2.29; 95% CI: 1.73-3.04; P < 0.001), low electrocardiogram voltage in peripheral leads (OR: 3.61; 95% CI: 2.38-5.49; P < 0.001), skeletal myopathy (OR: 3.42; 95% CI: 1.60-7.31; P = 0.001), absence of hypertension (OR: 2.28; 95% CI: 1.67-3.13; P < 0.001), and absence of left bundle branch block (OR: 3.58; 95% CI: 2.57-5.01; P < 0.001). A score containing these factors predicted a G+ result, ranging from 3% when all predictors were absent to 79% when ≥4 predictors were present. Internal validation provided a C-statistic of 0.74 (95% CI: 0.71-0.77) and a calibration slope of 0.94 (95% CI: 0.80-1.10). The C-statistic in the external validation cohort was 0.74 (95% CI: 0.71-0.78). CONCLUSIONS: The Madrid Genotype Score is an accurate tool to predict a G+ result in DCM/LVSD.