Faculty Bibliography

OBJECTIVES: The aim of the study was to evaluate the risk of cardiac events in patients with normal stress echocardiography (SE) who attained maximal age-predicted heart rate (APHR) compared with those who did not in the setting of both normal and abnormal SE. BACKGROUND: SE is an important tool in the risk stratification and prognosis of patients with known or suspected coronary artery disease (CAD). The prognostic value of a normal but submaximal SE (<85% of maximal APHR) is conflicting. METHODS: PubMed, EMBASE, and CENTRAL were searched from 1980 to September 2011 for SE studies reporting cardiac outcomes in patients with known or suspected CAD stratified by achieved APHR. Both hard events (cardiac death and myocardial infarction) and total cardiac events (revascularization procedures in addition to hard events) were analyzed separately. Data on all-cause mortality were obtained when available. RESULTS: Fourteen studies with 11,542 patients followed up for a mean duration of 32 months fulfilled the inclusion criteria. In 8 studies with 4,577 patients, the risk of hard events with normal SE (both exercise and dobutamine) was 70% higher in patients who achieved submaximal compared with those with maximal APHR (annualized event rate 2.08% vs. 0.77%; p = 0.0008; 95% confidence interval [CI]: 1.25 to 2.31). In 7 studies with 5,798 patients, the risk of total cardiac events with normal SE (both exercise and dobutamine) was 127% higher in patients who achieved submaximal compared with those with maximal APHR (annualized event rate 1.87% vs. 1.02%; p < 0.0001; 95% CI: 1.54 to 3.34). The risk of total cardiac events was 278% higher in patients with abnormal SE with submaximal APHR compared with those with normal SE with submaximal APHR (p < 0.0001; 95% CI: 2.81 to 5.08). There was a trend toward increased all-cause mortality in patients with normal SE with submaximal compared with maximal APHR (relative risk: 1.36; p = 0.15; 95% CI: 0.89 to 2.09). CONCLUSIONS: Patients with submaximal APHR in the setting of normal SE have a higher risk of cardiovascular events than those who attained maximal stress test. Thus, the results of submaximal APHR in the setting of normal SE should be taken into consideration for more accurate risk stratification and prognosis.

CONTEXT: beta-Blockers remain the standard of care after a myocardial infarction (MI). However, the benefit of beta-blocker use in patients with coronary artery disease (CAD) but no history of MI, those with a remote history of MI, and those with only risk factors for CAD is unclear. OBJECTIVE: To assess the association of beta-blocker use with cardiovascular events in stable patients with a prior history of MI, in those with CAD but no history of MI, and in those with only risk factors for CAD. DESIGN, SETTING, AND PATIENTS: Longitudinal, observational study of patients in the Reduction of Atherothrombosis for Continued Health (REACH) registry who were divided into 3 cohorts: known prior MI (n = 14,043), known CAD without MI (n = 12,012), or those with CAD risk factors only (n = 18,653). Propensity score matching was used for the primary analyses. The last follow-up data collection was April 2009. MAIN OUTCOME MEASURES: The primary outcome was a composite of cardiovascular death, nonfatal MI, or nonfatal stroke. The secondary outcome was the primary outcome plus hospitalization for atherothrombotic events or a revascularization procedure. RESULTS: Among the 44,708 patients, 21,860 were included in the propensity score-matched analysis. With a median follow-up of 44 months (interquartile range, 35-45 months), event rates were not significantly different in patients with beta-blocker use compared with those without beta-blocker use for any of the outcomes tested, even in the prior MI cohort (489 [16.93%] vs 532 [18.60%], respectively; hazard ratio [HR], 0.90 [95% CI, 0.79-1.03]; P = .14). In the CAD without MI cohort, the associated event rates were not significantly different in those with beta-blocker use for the primary outcome (391 [12.94%]) vs without beta-blocker use (405 [13.55%]) (HR, 0.92 [95% CI, 0.79-1.08]; P = .31), with higher rates for the secondary outcome (1101 [30.59%] vs 1002 [27.84%]; odds ratio [OR], 1.14 [95% CI, 1.03-1.27]; P = .01) and for the tertiary outcome of hospitalization (870 [24.17%] vs 773 [21.48%]; OR, 1.17 [95% CI, 1.04-1.30]; P = .01). In the cohort with CAD risk factors only, the event rates were higher for the primary outcome with beta-blocker use (467 [14.22%]) vs without beta-blocker use (403 [12.11%]) (HR, 1.18 [95% CI, 1.02-1.36]; P = .02), for the secondary outcome (870 [22.01%] vs 797 [20.17%]; OR, 1.12 [95% CI, 1.00-1.24]; P = .04) but not for the tertiary outcomes of MI (89 [2.82%] vs 68 [2.00%]; HR, 1.36 [95% CI, 0.97-1.90]; P = .08) and stroke (210 [6.55%] vs 168 [5.12%]; HR, 1.22 [95% CI, 0.99-1.52]; P = .06). However, in those with recent MI (</=1 year), beta-blocker use was associated with a lower incidence of the secondary outcome (OR, 0.77 [95% CI, 0.64-0.92]). CONCLUSION: In this observational study of patients with either CAD risk factors only, known prior MI, or known CAD without MI, the use of beta-blockers was not associated with a lower risk of composite cardiovascular events.

BACKGROUND: Young patients (aged