Minor Isolated Q Waves and Cardiovascular Events in the MESA Study

Abstract

BACKGROUND The significance of minor isolated Q waves in the resting electrocardiograms (ECGs) of apparently healthy individuals is unknown. OBJECTIVE To examine the association between minor isolated Q waves and incident cardiovascular disease events in the Multi-Ethnic Study of Atherosclerosis (MESA). DESIGN This analysis included 6551 MESA participants (38% white, 28% black, 22% Hispanic, 12% Chinese) who were free of cardiovascular disease at enrollment. Cox proportional hazards models were used to examine the association between minor isolated Q waves defined by the Minnesota ECG Classification with adjudicated incident cardiovascular events. RESULTS During up to 7.8 years of follow-up, 423 events occurred, with a rate of 10.7 events per 1000 person-years. A significant interaction between minor isolated Q waves and race/ethnicity was observed (P = .030). In models stratified by race/ethnicity and adjusted for demographics, socioeconomic status, common cardiovascular risk factors, and other ECG abnormalities, presence of isolated minor Q waves was significantly associated with incident cardiovascular events in Hispanics (hazard ratio [HR] 2.62; 95% confidence interval [CI], 1.42-4.82), but not in whites (HR 0.65; 95% CI, 0.32-1.33) or blacks (HR 1.46; 95% CI, 0.74-2.89). Despite the statistically significant association in the Chinese population, the small number of events precluded solid conclusions in this race/ethnicity. CONCLUSION The prognostic significance of minor isolated Q waves varies across races/ethnicities; they carry a high risk for future cardiovascular events in apparently healthy Hispanics, but not in whites or blacks.

Vitamin D deficiency and electrocardiographic subclinical myocardial injury: Results from National Health and Nutrition Examination Survey‐III

“…CIIS has been shown to predict CVD and all‐cause mortalities among those without apparent CVD . Other electrocardiographic markers which are also associated with increased mortality include QRS duration and minor Q waves, but they only rely on 1 or 2 data points . In contrast, the application of a scoring system, such as CIIS may be a more sensitive indicator of myocardial injury.…”

“…11 Other electrocardiographic markers which are also associated with increased mortality include QRS duration and minor Q waves, but they only rely on 1 or 2 data points. 25,26 In contrast, the application of a scoring system, such as CIIS may be a more sensitive indicator of myocardial injury. It has also been shown that the CIIS improves the accuracy of the standard 12-lead ECG to identify patients with SC-MI.…”

Subclinical Myocardial Injury Identified by Cardiac Infarction/Injury Score and the Risk of Mortality in Men and Women Free of Cardiovascular Disease

“…15,16 Although many individual electrocardiogram variables predict mortality, a large number of persons with subclinical myocardial injury will be missed if abnormalities are examined separately. The application of a scoring system, such as CIIS, to identify at-risk individuals was shown in this study as a large group of persons without clinical CVD had an increased risk of CVD and all-cause mortalities.…”

Borderline Q-waves in individuals without overt cardiovascular disease: Relations with adiposity, subclinical atherosclerosis and vascular stiffness

“…Clinical characteristics and risk factor profiles of individuals with these borderline Q-waves are not fully elucidated, especially not in individuals without known CVD. In large cohort studies, it was observed that individuals with borderline Q-waves tended to be older, more often suffering from diabetes mellitus and hypertension and also seemed to have a worse kidney function than individuals without Q-waves [4][5][6]. Although these characteristics suggest an unfavorable metabolic profile, associations with body mass index (BMI) were not demonstrated [4,6].…”

“…Furthermore, the clinical relevance of a borderline Q-wave, especially an isolated borderline Q-wave, in an individual without previously known CVD is not clear. The literature is inconclusive on the importance of borderline, and especially isolated borderline Q-waves in individuals free of established CVD, with some studies reporting increased cardiovascular risk in individuals with borderline Q-waves [4], some reporting no increased cardiovascular risk [5] and some studies reporting increased cardiovascular risk for non-isolated borderline Q-waves only [6].…”