CHICAGO – A novel risk score has been developed for predicting the risk of in-hospital mortality in patients with takotsubo cardiomyopathy.
The new risk score’s unique strength is that it was developed using hospital data on a huge patient population with this rare and incompletely understood cardiac condition: 10,582 patients hospitalized for takotsubo cardiomyopathy in seven U.S. states, Dr. David P. Kao reported at the American Heart Association scientific sessions.
He used multivariate logistic regression analysis to identify seven independent characteristics predictive of mortality in the study population. Their collective area under the curve as predictors was 0.70, which is considered good. And while the overall in-hospital mortality rate was low at 4.4%, it varied enormously depending upon how many of the seven risk factors were present, according to Dr. Kao of the University of Colorado, Denver.
In-hospital mortality ranged from 1.6% in the 2,585 patients with none of the risk factors to 19.6% in those with three or more. The 616 patients with at least three risk factors accounted for 22% of all in-hospital deaths in patients with takotsubo cardiomyopathy in California, New York, New Jersey, Colorado, West Virginia, New Hampshire, and Vermont during 2006-2012.
Intracranial hemorrhage, which was present in 2% of hospitalized takotsubo cardiomyopathy patients, was the most potent predictor both of in-hospital mortality and major adverse events. In multivariate analysis, intracranial hemorrhage was independently associated with a 6.8-fold increased risk of in-hospital mortality. The other mortality risk factors and their associated odds ratios were age 60 years or older, with a 1.8-fold risk; Asian race, 1.8-fold; male sex, 1.9-fold; acute renal failure, 4.1-fold; atrial fibrillation or flutter, 1.7-fold; and stroke, 2.9-fold.
The simple, user-friendly risk score is derived by totaling the number of risk factors present in a given hospitalized patient. The presence of each additional risk factor increased the odds of in-hospital death by 2.2-fold, according to Dr. Kao.
Dr. JoAnn Lindenfeld
Takotsubo cardiomyopathy is marked by acute, typically rapidly reversible left ventricular dysfunction without evidence of epicardial coronary artery occlusion. It occurs most often in postmenopausal women in response to emotional or physical stress. Indeed, 89% of the more than 10,000 affected patients in this series were women.
Most adverse events in patients with takotsubo cardiomyopathy occur during their first hospitalization for the disorder. In this large series, 22% of patients experienced major adverse events, including ventricular arrhythmias, acute heart failure, cardiogenic shock, pulmonary edema, or ventricular rupture.
In a separate multiple logistic regression analysis, Dr. Kao and coinvestigator Dr. JoAnn Lindenfeld, also of the University of Colorado, identified eight characteristics independently predictive of in-hospital major adverse events. Five of them were also predictors of in-hospital mortality: intracranial hemorrhage, male gender, stroke, atrial fibrillation/flutter, and acute renal failure. The other three were age less than 60, substance abuse, and anemia. The major adverse event rate ranged from 10% in patients with none of the risk factors to 56% in the 242 patients having four or more. The 1,057 patients with three or more risk factors had a 47% major adverse event rate and accounted for 20% of all such events.
Dr. Kao reported having no financial conflicts related to this study.