Background

There is limited information about the long-term survival of older patients after myocardial infarction (MI).

Methods and results

CRUSADE (Can rapid risk stratification of unstable angina patients suppress adverse outcomes with early implementation of the ACC/AHA guidelines) was a registry of MI patients treated at 568 US hospitals from 2001 to 2006. We linked MI patients aged ≥65 years in CRUSADE to their Medicare data to ascertain long-term mortality (defined as 8 years post index event). Long-term unadjusted Kaplan-Meier mortality curves were examined among patients stratified by revascularization status. A landmark analysis conditioned on surviving the first year post-MI was conducted. We used multivariable Cox regression to compare mortality risks between ST-segment-elevation myocardial infarction and non-ST-segment-elevation myocardial infarction patients. Among 22 295 MI patients ≥ age 65 years (median age 77 years), we observed high rates of evidence-based medication use at discharge: aspirin 95%, β-blockers 94%, and statins 81%. Despite this, mortality rates were high: 24% at 1 year, 51% at 5 years, and 65% at 8 years. Eight-year mortality remained high among patients who underwent percutaneous coronary intervention (49%), coronary artery bypass graft (46%), and among patients who survived the first year post-MI (59%). Median survival was 4.8 years (25th, 75th percentiles 1.1, 8.5); among patients aged 65-74 years it was 8.2 years (3.3, 8.9) while for patients aged ≥75 years it was 3.1 years (0.6, 7.6). Eight-year mortality was lower among ST-segment-elevation myocardial infarction than non-ST-segment-elevation myocardial infarction patients (53% versus 67%); this difference was not significant after adjustment (hazard ratio 0.94, 95% confidence interval, 0.88-1.00).

Conclusions

Long-term mortality remains high among patients with MI in routine clinical practice, even among revascularized patients and those who survived the first year.

Background

PROMISE (PROspective Multicenter Imaging Study for Evaluation of Chest Pain) found that initial use of at least 64-slice multidetector computed tomography angiography (CTA) versus functional diagnostic testing strategies did not improve clinical outcomes in stable symptomatic patients with suspected coronary artery disease (CAD) requiring noninvasive testing.

Objective

To conduct an economic analysis for PROMISE (a major secondary aim of the study).

Design

Prospective economic study from the U.S. perspective. Comparisons were made according to the intention-to-treat principle, and CIs were calculated using bootstrap methods. (ClinicalTrials.gov: NCT01174550).

Setting

190 U.S. centers.

Patients

9649 U.S. patients enrolled in PROMISE between July 2010 and September 2013. Median follow-up was 25 months.

Measurements

Technical costs of the initial (outpatient) testing strategy were estimated from Premier Research Database data. Hospital-based costs were estimated using hospital bills and Medicare cost-charge ratios. Physician fees were taken from the Medicare Physician Fee Schedule. Costs were expressed in 2014 U.S. dollars, discounted at 3% annually, and estimated out to 3 years using inverse probability weighting methods.

Results

The mean initial testing costs were $174 for exercise electrocardiography; $404 for CTA; $501 to $514 for pharmacologic and exercise stress echocardiography, respectively; and $946 to $1132 for exercise and pharmacologic stress nuclear testing, respectively. Mean costs at 90 days were $2494 for the CTA strategy versus $2240 for the functional strategy (mean difference, $254 [95% CI, -$634 to $906]). The difference was associated with more revascularizations and catheterizations (4.25 per 100 patients) with CTA use. After 90 days, the mean cost difference between the groups out to 3 years remained small.

Limitation

Cost weights for test strategies were obtained from sources outside PROMISE.

Conclusion

Computed tomography angiography and functional diagnostic testing strategies in patients with suspected CAD have similar costs through 3 years of follow-up.

Primary funding source

National Heart, Lung, and Blood Institute.