Incidence and prognosis of non-Q-wave vs. Q-wave myocardial infarction following catheter-based reperfusion therapy.
BACKGROUND
The clinical importance of classifying myocardial infarction (MI) into non-Q-wave (NQWMI) vs. Q-wave (QWMI) subsets is controversial and might depend on the therapeutic reperfusion strategy employed. The prognostic implications of NQWMI development following primary percutaneous coronary intervention (PCI) have not been reported.


OBJECTIVE
To examine the incidence, determinants and prognostic implications of NQWMI vs. QWMI development following primary PCI.


METHODS
The ACSIS Registry, a 2-month nationwide survey conducted biennially, prospectively collects data from all MI admissions in Israel.


METHODS
Outcomes were compared among patients managed by primary PCI who subsequently developed NQWMI vs. QWMI. Independent predictors of Q-wave development and 1-year mortality were determined by multivariate stepwise logistic regression analysis and Cox proportional hazard model, respectively.


RESULTS
Of 4537 MI patients with ST-segment elevation on admission, 1230 (27%) were treated with primary PCI. A discharge diagnosis of NQWMI was made in 259 (21.1%) patients. The baseline features and PCI strategies employed were similar among NQWMI vs. QWMI patients, though peak creatine kinase levels were higher (median 795 U/l vs. 1681 U/l, P = 0.0001) and severe left ventricular ejection fraction (LVEF) impairment (<40%) more frequent (22.6% vs. 43.9%, P < 0.0001), in the latter group. Mortality at 1-year was significantly lower in NQWMI vs. QWMI patients (3.9% vs. 10.8%, P log-rank = 0.001). By Cox proportional hazard analysis, NQWMI vs. QWMI was an independent predictor of freedom from 1-year mortality [HR = 0.34 (95% CI: 0.15-0.79), P = 0.01].


CONCLUSIONS
The diagnosis of NQWMI after primary PCI is associated with an excellent prognosis independent of established prognosticators, including LVEF.
Department of Cardiology, Tel Aviv Medical Center, Tel Aviv, Israel. ahalkin@netvision.net.il
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Halkin
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Fourey
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Roth
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Boyko
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Behar
D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D004562:Electrocardiography; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy; D015425:Myocardial Reperfusion / Q000009:adverse effects* / Q000379:methods; D011379:Prognosis