điều trị đã được nhìn thấy đầu bài, ngẫu nhiên, lợi ích sống còn quan sát thấy trong MADIT II bắt đầu khoảng 9 tháng sau khi thiết bị đã được cấy ghép. Các tác giả cho rằng sự khác biệt này có thể là do một dân số có nguy cơ thấp | CHAPTER 14 DEVICES FOR THE TREATMENT OF HEART FAILURE 189 therapy was seen early post-randomization the survival benefit observed in MADIT II began approximately 9 months after the device was implanted. The authors suggested that this difference may be due to a lower-risk population enrolled in MADIT II the absence of arrhythmia as risk stratification for entry and or the use of more aggressive medical treatment. Regardless of the explanation this observation may be important when considering the timing of device placement in eligible patients. Prophylactic Defibrillator Implantation in Patients with Nonischemic Dilated Cardiomyopathy Trial While MADIT II enrolled exclusively post-MI patients with an ischemic cause of left ventricular systolic dysfunction and heart failure the DEFINITE trial was the first randomized trial of primary prevention therapy with an ICD in nonischemic cardiomyopathy Such patients also exhibit high rates of SCD however until recently there has been little consensus regarding the management of SCD risk in such patients. This may be due in part to limitations in objective risk assessment in that no invasive or noninvasive testing procedure has been shown to accurately determine which nonischemic heart failure patient is likely to die suddenly. Also clouding the picture were older observations suggesting that the prophylactic administration of an antiarrhyth-mic agent amiodarone might prolong survival in nonischemic cardiomyopathy The DEFINITE trial was a prospective evaluation of 458 patients with nonischemic dilated cardiomyopathy. Entry criteria included an ejection fraction of 35 a history of symptomatic heart failure and the presence of ambient arrhythmias defined as an episode of nonsustained ventricular tachycardia or at least 10 premature ventricular contractions per 24-hour period on continuous ambulatory electrocardiographic monitoring. Two hundred and twenty-nine patients were randomized to each arm of the .
