Clinical significance of Q waves in ischemic cardiomyopathy

Abstract

Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): CIBER-CV AIMS The scintigraphic translation of Q waves in patients with ischemic cardiomyopathy and LVEF < 40% has not yet been assessed. The aim of this study was to explore the relationship between Q waves and necrotic tissue and to analyze their impact in prognosis. METHODS AND RESULTS A retrospective study enrolling 487 consecutive patients (67,0 [57,4 – 75,4] years), with ischemic cardiomyopathy, LVEF <40% and narrow QRS who underwent stress-rest SPECT was conducted. Patients with Q waves (320 patients [65,7%]) had less comorbidity and ischemia, but more necrosis. Q waves correlated poorly with lack of viability (AUC = 0,63) and were independently associated with the subendocardial extent of the necrosis. After a follow-up of 5,07 years, the primary outcome (cardiovascular death, heart failure hospitalization or myocardial infarction) occurred in 192 (39,4%) patients, without differences between groups in multivariate analysis. After accounting for non-cardiovascular death as a competitive risk, the interaction between >10% of ischemia and revascularization remained in Cox model both in the total cohort (aHR= 0,46 [0,24 – 0,86]), and in patients with Q waves (aHR = 0,27 [0,11–0,69]). CONCLUSION Patients with ischemic cardiomyopathy with Q waves have larger subendocardial scarring and more transmural necrosis, although correlation between Q waves and transmural scarring is poor. Revascularization if >10% ischemia is present is associated with a better prognosis. Ischemia burden should be assessed and accordingly treated in these patients, and no differences in management should be made in the presence of Q waves. Table 1. Cox proportional hazards model Total cohort (N = 471) Patients with Q waves (N = 315) aHR p-value 95% CI aHR p-value 95% CI Age (per year) 1,02 0,007 1,01 - 1,04 n.s. Diabetes mellitus 1,35 0,047 1,00 - 1,81 1,54 0,016 1,09 - 2,20 eGFR < 60 ml/min 1,59 0,005 1,15 - 2,21 1,96 <0,001 1,36 - 2,82 Previous HF hospitalization 1,71 0,002 1,23 - 2,38 1,76 0,007 1,17 - 2,64 Previous PCI 1,32 0,069 0,98 - 1,78 n.s. Previous CABG n.s. 1,77 0,009 1,15 - 2,72 Angina or dyspnea 1,68 0,001 1,24 - 2,28 1,71 0,004 1,19 - 2,46 Indexed TDV (per quartile) 1,16 0,047 1,02 - 1,33 n.s. Revascularization*ischemia > 10% 0,46 0,015 0,24 - 0,86 0,27 0,006 0,11 - 0,69 Cox regression for the primary endpoint (cardiovascular death, heart failure hospitalization or myocardial infarction), accounting for non-cardiovascular death as a competitive risk. Abstract Figure. Survival for the primary endpoint