Implantable cardioverter‐defibrillator therapy in device recipients who survived a cardiac arrest associated with a reversible cause

Abstract

We show higher rates of appropriate ICD therapy in survivors of SCA associated with reversible causes other than MI/ischemia. This finding, in conjunction with the previously demonstrated lower all-cause mortality noted in the presence of an ICD in SCA survivors with reversible etiology other than MI/ischemia, further supports consideration of ICD implantation in this population.

Secondary prevention of sudden cardiac death

“…They found, however, that appropriate ICD therapy still occurred in 23% of these patients, highlighting the substantial risk of incident ventricular arrhythmias regardless of presenting rhythm in patients with prior MI presenting with acute coronary syndrome and sustained VT/VF. Similarly, over a mean follow-up of 4 years, Gupta and colleagues 20 identified appropriate ICD therapies in 18% of patients with a history of VT/VF in the setting of acute ischemia. Finally, the relative timing of arrhythmia in relation to reperfusion may further modify arrhythmia risk.…”

“…While the findings of Ladejobi and colleagues 19 would suggest that contemporary revascularization strategies may abrogate or minimize the survival benefit of ICD therapy in patients with sustained arrhythmias in the setting of acute cardiac ischemia, the role of ICD therapy in this setting remains an open question. 20 , 21 For example, van Dijk and colleagues 21 evaluated the incidence of ICD therapy in patients with prior MI presenting with sustained arrhythmia (67% VF, 33% VT) in the setting of acute coronary syndrome (22% ST elevation MI [STEMI], 68% non-STEMI, 10% unstable angina) and an LVEF ≥35%. Over a mean follow-up of 5 years, appropriate ICD therapy occurred in 46% of patients.…”

“…In addition, for patients with ventricular arrhythmias in the context of acute ischemia, recent data reflect a clinically significant rate of appropriate ICD therapy in this population. 20 , 21 The relative timing of VT/VF in relation to reperfusion may also be an important risk marker, 22 in addition to other clinical factors including a prior history of MI, index presentation with cardiogenic shock, time to reperfusion, and residual ischemia. Whether additional diagnostic tools, such as use of LGE presence and extent by CMR, 31 might better delineate risk in this population warrants future investigation.…”

The boundaries between primary and secondary prevention with defibrillators after acute myocardial infarction: Gray areas of the terminology and definition

“…For VAs occurring more than 48 to 72 hours after an acute MI, scar formation is of primary importance. 13,14 The MVT is considered a marker of the permanent arrhythmic substrate (ie, fibrosis and reentry) and an increased longterm risk of arrhythmia recurrence and sudden cardiac death (SCD).…”

“…19,20 Published guidelines on the use of ICD therapy exclude cases in which there are "transient or reversible causes," 21 although in the specifics of its application this exclusion is somewhat controversial. 1,13,16 We would like to thanks to authors for sharing their experience and findings. As the authors stated, the clinician must decide whether an ICD is appropriate on an individual basis.…”