Title

Predictors and implications of Q-waves in ST-elevation acute coronary syndromes

UMMS Affiliation

Center for Outcomes Research; Department of Surgery

Date

2-3-2009

Document Type

Article

Medical Subject Headings

Acute Coronary Syndrome; Aged; Electrocardiography; Female; Hospital Mortality; Humans; Male; Middle Aged; Prognosis; Risk Factors; Survival Analysis

Disciplines

Health Services Research

Abstract

BACKGROUND: Q-waves in ST-elevation acute coronary syndromes carry adverse implications. We sought to determine the frequency, predictors, and implications of Q-waves in the current era that includes primary percutaneous coronary interventions.

METHODS: There were 14,916 patients evaluated in a multicenter observational study. They presented with ST-elevation acute coronary syndromes between 1999 and 2006. Clinical variables were compared between patients with versus without presenting Q-waves, with an additional comparison in the latter group between those with versus without subsequent development of Q-waves.

RESULTS: ST-elevation myocardial infarction occurred in 88.6% of patients. Q-waves were present on the initial electrocardiogram in 3929 patients and developed later in an additional 3085 patients. The incidence of Q-waves at presentation or during hospitalization decreased from 61% to 39% between 1999 and 2006 (linear trend P<.001). Both presenting and subsequent Q-waves were associated with greater likelihood of coronary occlusions and higher cardiac marker elevations (P <.001). Multivariate analysis showed that presenting Q-waves were associated with male sex (odds ratio [OR] 1.28), increased age (OR 1.06 per 5 years), diabetes (OR 1.26), smoking (OR 1.11), chronic aspirin (OR 0.79), acute aspirin (OR 0.87), other chronic cardiac medications (OR 0.80), prior heart failure (OR 0.67), and prior coronary artery disease (OR 0.61). Presenting Q-waves were independently associated with increased in-hospital mortality (OR 1.46), but Q-waves at presentation or during hospitalization did not impact 6-month mortality.

CONCLUSIONS: Q-waves in ST-elevation acute coronary syndromes are decreasing in incidence. Q-waves are a major determinant of in-hospital mortality, and targeted interventions should be directed to these high-risk patients.

Rights and Permissions

Citation: Am J Med. 2009 Feb;122(2):144-51. Link to article on publisher's site

Related Resources

Link to Article in PubMed

PubMed ID

19185091