The presence of a T-wave alternans pattern on echocardiography identifies patients with stage II or III non-ischemic cardiomyopathy most likely to benefit from implantable cardioverter-defibrillators, according to results from a late-breaking trial presented at the scientific session of the American College of Cardiology.

The ALPHA (T-wave ALternans in Patients with Heart fAilure) Trial was done to assess predictive power of echocardiographic findings on risk for ventricular arrhythmias among patients with stage II and III non-ischemic cardiomyopathy

The study involved 446 patients with cardiomyopathy of non-ischemic origin (with normal or near normal coronary arteries), all of whom had left ventricle ejection fractions less than 40 percent and no previous malignant arrhythmias.

Patients underwent testing and were followed for 18 to 24 months to assess the combined rates of cardiac death plus life-threatening arrhythmias, as well as rates of total mortality and of sudden death plus life-threatening arrhythmias.

The prognostic value of testing among study participants suggests that patients with an abnormal test (65 percent of patients) have a four-fold higher risk of cardiac death and life-threatening arrhythmias. The study also demonstrated that patients with a normal TWA test (35 percent of patients) have a very good prognosis and are therefore unlikely to benefit from a device.

“The ability to determine if heart failure patients are at high risk of life-threatening arrhythmias is essential to determining the best method of treatment, including the option of using an ICD or maintaining pharmacologic therapy. The predictive value of a TWA test among this population demonstrated accuracy in identifying high-risk patients that will likely see benefit from an ICD device,” said Gaetano M De Ferrari, MD, of the Department of Cardiology of the San Matteo Hospital in Pavia, Italy, and contributing author of the study. “Presently, all patients with stage II and III disease with left ventricle ejection fraction of less than 35 percent are considered candidates to an ICD. The ALPHA study strongly suggests that one third of these patients will have a normal TWA test and will not benefit from the ICD. Knowing this, we are able to better treat the two thirds of patients that really need the device.”