Hemodynamically Tolerated Ventricular Tachycardia With Mildly Impaired Ejection Fraction: Do These Patients Have VT/VF Recurrence and ICD Therapies?

ICDs for Patients With Stable VT, Cardiomyopathy, and Relatively Preserved LVEF: Core Therapy, Precision Medicine, or Indication Creep?

“…The 2-year actuarial incidence of any ICD-treated VT/VF reported by Gula et al 15 (55%) appears to be less than previously reported by Böcker et al 9 (77%) and by Glikson et al 10 (67%). This may reflect either interim improvement in patient prognosis and ICD technology or that Gula et al 15 restricted their study to patients with relatively preserved LVEF. The only previous comparable study of patients with both stable VT and relatively preserved LVEF, comprising 17 patients, reported a 4-year actuarial incidence of any ICD-treated VT/ VF of 80% (if linearity is assumed, 40% after 2 years).…”

“…Frequent recurrence of VT in the patients of Gula et al 15 is expected, as the arrhythmogenic substrate for hemodynamically stable VT in most patients with cardiomyopathy includes a continuously present re-entrant circuit that will sustain VT when initiated by a trigger. The 2-year actuarial incidence of any ICD-treated VT/VF reported by Gula et al 15 (55%) appears to be less than previously reported by Böcker et al 9 (77%) and by Glikson et al 10 (67%). This may reflect either interim improvement in patient prognosis and ICD technology or that Gula et al 15 restricted their study to patients with relatively preserved LVEF.…”

“…The only previous comparable study of patients with both stable VT and relatively preserved LVEF, comprising 17 patients, reported a 4-year actuarial incidence of any ICD-treated VT/ VF of 80% (if linearity is assumed, 40% after 2 years). 10 Note that the study of Gula et al 15 shares bias of previous studies of having included many patients with demonstrated resistance to AAD. Whether or not these recurrence rates are representative of drug-naïve patients with hemodynamically stable VT and relatively preserved LVEF cannot be determined from available data.…”

“…In this issue of the Canadian Journal of Cardiology, Gula et al 15 provide additional data relative to recurrence of VT/ VF from 64 patients with cardiomyopathy and LVEF 0.36 to 0.49 who had received ICDs after hemodynamically stable VT. The primary outcome variable was the first occurrence of ICD-treated VT/VF following a 7-day blanking period after ICD placement.…”

“…Whether or not these recurrence rates are representative of drug-naïve patients with hemodynamically stable VT and relatively preserved LVEF cannot be determined from available data. Nevertheless, the study of Gula et al 15 nearly triples the number of published patients with hemodynamically stable VT, cardiomyopathy, and relatively preserved LVEF addressing the natural history of VT/VF recurrence.…”