Acute myocardial infarction and lesion location in the left circumflex artery: importance of coronary artery dominance

AIMS

Due to the limitations of 12-lead ECG, occlusions of the left circumflex artery (LCX) are more likely to present as non-ST-elevation acute coronary syndrome (NSTEACS) compared with other coronary arteries. We aimed to study mortality in patients with LCX lesions and to assess the importance of coronary artery dominance on triage of these patients.

METHODS AND RESULTS

From the Eastern Danish Heart Registry, 3,632 NSTEACS and 3,907 ST-elevation myocardial infarction (STEMI) consecutive, single-vessel disease patients were included. LCX was the culprit in 25% of NSTEACS and 14% of STEMIs (p<0.001). LCX lesions presented predominantly as STEMI in left dominant coronary arteries compared with NSTEACS (46% vs. 30%, p<0.001). Higher 30-day mortality was found in LCX-STEMI compared with LCX-NSTEACS (HR 7.9, 95% CI: 3.2-19.7, p<0.001) with no difference in long-term mortality (HR 0.9, 95% CI: 0.7-1.2, p=0.5). LCX-NSTEACS were not associated with higher mortality compared with other NSTEACS lesions.

CONCLUSIONS

The 12-lead ECG seems sufficient for triage of patients with LCX lesions as a majority of patients with a large LCX due to a dominant left coronary artery present as STEMI. Patients with LCX-NSTEACS do not have higher mortality compared with patients with LCX-STEMI or NSTEACS with lesions in other coronary territories.

Short and long-term survival after primary percutaneous coronary intervention in young patients with ST-elevation myocardial infarction

The long-term prognosis of patients with ST-elevation myocardial infarction (STEMI) aged 45 years or younger and differences according to gender have not been well characterized.

METHODS

We included 16,685 consecutive STEMI patients from 2003 to 2012 (67,992 patient-years follow-up) from the Eastern Danish Heart Registry and the Swedish Coronary Angiography and Angioplasty Registry who were treated with primary percutaneous coronary intervention (PCI).

RESULTS

We identified 1026 (6.2%) patients up to 45 years of age (mean age: 40.7 vs. 66.3 years, P<0.001). Patients in the young group were predominantly men (79.7% vs. 71.9%) and smokers (71.2% vs. 44.2%, P<0.001) but with a lower prevalence of hypertension (17.3% vs. 39.3%), hyperlipidemia (18.0% vs. 23.8%), diabetes (9.0% vs. 12.4%) and previous myocardial infarction (6.9% vs. 12.2%, all P<0.001) compared with older patients. Young patients had a 0.8% annual mortality. During the follow-up period 6.3% of young patients died vs. 28.5% of older patients (P<0.001). Both 30-day-mortality (adjusted hazard ratio [HR]=0.26, 95% confidence interval [CI]: 0.12-0.54, P<0.001) and mortality after 30 days and onwards (HR=0.25, CI: 0.17-0.37, P<0.001) were significantly lower in the young group. There was no difference in short-term (HR=0.78, CI: 0.32-1.90, P=0.59) or long-term (HR=0.62, CI: 0.33-1.91, P=0.59) mortality between women and men in the young group (HR=0.79, CI: 0.21-1.80, P=0.39).

CONCLUSIONS

STEMI patients, aged 45 years or younger, have an excellent prognosis after treatment with primary PCI. Long-term annual survival is more than 99% in these patients. Young women with STEMI do not have a worse long-term prognosis than young men with STEMI.

The Prognostic Value of Left Atrial Peak Reservoir Strain in Acute Myocardial Infarction Is Dependent on Left Ventricular Longitudinal Function and Left Atrial Size

Background—

Peak atrial longitudinal strain (PALS) during the reservoir phase has been proposed as a measure of left atrium function in a range of cardiac conditions, with the potential for added pathophysiological insight and prognostic value. However, no studies have assessed the interrelation of PALS and left ventricular longitudinal strain (global longitudinal strain) in large-scale populations in regard to prognosis.

Methods and Results—

We prospectively included 843 patients (mean age 62.1±11.8; 74% male) with acute myocardial infarction and measured global longitudinal strain, left atrium volumes, and PALS within 48 hours of admission. PALS was related to a composite outcome of death and heart failure hospitalization. Reduced PALS was associated with hypertension, diabetes mellitus, and Killip class >1 ( P <0.05 for all). Reduced PALS was associated with impairment of all measures of left ventricular systolic and diastolic function, and the correlation between global longitudinal strain and PALS was highly significant ( P <0.001; r =–0.71). During follow-up (median 23.0 months Q1–Q3, 16.8–26.0), a total of 76 patients (9.0%) reached the composite end point of which 47 patients died (5.6%), and 29 patients were hospitalized for heart failure (3.4%). PALS was significantly associated with outcome (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.85–0.90; P <0.001); however, no independent effect of PALS (HR, 1.00; 95% CI, 0.94–1.05; P =0.87) was found when adjusting for global longitudinal strain (HR, 1.20; 95% CI, 1.09–1.33; P <0.001), maximum left atrium volume before mitral valve opening (HR, 1.02; 95% CI, 1.01–1.04; P =0.006), and age (HR, 1.06; 95% CI, 1.03–1.08; P <0.001).

Conclusions—

PALS provides a composite measure of left ventricular longitudinal systolic function and maximum left atrium volume before mitral valve opening, and as such contains no added information when these readily obtained measures are known.