Preventive implantation of implantable cardioverter defibrillator in patients with ischemic heart disease and aortocoronary bypass

Uvod: Naprasna srčana smrt (NSS) je prirodna smrt koja nastaje iz srčanih razloga, unutar jednog sata od početka akutnih kardiovaskularnih događaja, a prethodi joj nagli gubitak svesti. Najčešći uzrok je koronarna bolest (80%). Naprasna srčana smrt može nastupiti u bilo koje vreme od srčanog infarkta, a usled pojave komorske fibrilacije (VF) ili brze prolongirane komorske tahikardije (VT) koja alterira u VF. Perioperativni srčani zastoj kod operacija na otvorenom srcu se javlja u 0,7-2,9% bolesnika. Preživljavanje ovih bolesnika je 17-79%. Terapije beta blokatorima i amiodaronom nije dala zadovoljavajuće rezultate u prevenciji NSS uzrokovane malignim poremećajima ritma za razliku od profilaktičke implantacije implantabilnog kardioverter defibrilatora (ICD). Ovo je potvrdilo nekoliko studija: Multicenter Automatic Defibrillator Implantation Trial (MADIT), The Multi-center Unsustained Tachycardia Trial (MUSTT), MADIT II i Sudden Cardiac Death-Heart Failure Trial (SCD-HeFT). U The Coronary-Artery Bypass Graft-Patch (CABG-Patch) studiji primarne prevencije NSS, u koju su, kao i kod nas, uključeni bolesnici kojima je urađena hirurška revaskularizacija miokarda i sa ejekcionom frakcijom EF≤36%, nije dokazana povezanost preživljavanja sa implantacijom ICD-a na osnovu kumulativnih krivi preživljavanja. Razlika između naše i CABG-Patch studije bila je u tome što su oni intraoperativno implantirali ICD bolesnicima koristeći epikardnu „patch― elektrodu, a mi između prvog i trećeg meseca po revaskularizaciji miokarda, plasirajući elektrodu transvenoznim putem, endokardno. Primarni cilj ove studije bio je da ispita da li je opšte preživljavanje duže kod bolesnika sa ishemijskom bolesti srca, EFLV≤35%, bez predhodno registrovanih NSVT, VT i VF, a posle učinjenog aortokoronarnog bajpasa i kojima je preventivno implantiran ICD, nego kod bolesnika sa antiaritmijskom terapijom β-blokatorima i Amiodaronom...Introduction: Sudden cardiac death (SCD) is a natural death from cardiac causes happening within one hour of the onset of acute cardiovascular symptoms, and is preceded by a sudden loss of consciousness. The most common cause of SCD is a coronary artery disease (80%). Sudden cardiac death can develop at any time after the acute myocardial infarction, due to the ventricular fibrillation (VF), or fast prolonged ventricular tachycardia (VT) progressing to VF. Cardiac revascularization, either by percutaneous coronary intervention (balloon angioplasty or stenting) or by surgical revascularization improves cardiac function, and with that survival of patients with low left ventricular ejection fraction (EF). Incidence of perioperative cardiac arrest after the open heart surgery is 0,7-2,9%. Survival of these patients is 17-79%. Beta blocker therapy, and amiodarone therapy haven’t yielded satisfying results in prevention of SCD caused by ventricular tachyarrhythmias as has prophylactic implantation of ICDs. This has been confirmed by several studies: Multicenter Automatic Defibrillator Implantation Trial (MADIT), The Multi-center Unsustained Tachycardia Trial (MUSTT), MADIT II and Sudden Cardiac Death-Heart Failure Trial (SCD-HeFT). Primary prevention of SCD trial - The CABG-Patch Trial included, as our trial did, patients with EF≤36%, that were scheduled for surgical revascularization. This trial didn’t show correlation of survival with ICD implantation. Difference between our trial and CABG-Patch was that in CABG-Patch trial they implanted ICD patch electrode epicardially during CABG surgery, while we implanted ICD patch electrode transvenously endocardially between the first and the third month after CABG surgery. The primary aim of the study was evaluation of overall survival of patients with IHD, EF≤35%, without prior NSVT,VT, VF and after CABG surgery with prophylactic ICD implantation compared to overall survival of patients on conservative medical therapy amiodarone and beta blockers..