Importance: Both noninvasive anatomic and functional testing strategies are now routinely
used as initial workup in patients with low-risk stable chest pain (SCP). Objective:
To determine whether anatomic approaches (ie, coronary computed tomography angiography
[CTA] and coronary CTA supplemented with noninvasive fractional flow reserve [FFRCT],
performed in patients with 30% to 69% stenosis) are cost-effective compared with functional
testing for the assessment of low-risk SCP. Design, Setting, and Participants: This
cost-effectiveness analysis used an individual-based Markov microsimulation model
for low-risk SCP. The model was developed using patient data from the Prospective
Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The model
was validated by comparing model outcomes with outcomes observed in the PROMISE trial
for anatomic (coronary CTA) and functional (stress testing) strategies, including
diagnostic test results, referral to invasive coronary angiography (ICA), coronary
revascularization, incident major adverse cardiovascular event (MACE), and costs during
60 days and 2 years. The validated model was used to determine whether anatomic approaches
are cost-effective over a lifetime compared with functional testing. Exposure: Choice
of index test for evaluation of low-risk SCP. Main Outcomes and Measures: Downstream
ICA and coronary revascularization, MACE (death, nonfatal myocardial infarction),
cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio
(ICER) of competing strategies. Results: The model cohort included 10 003 individual
patients (median [interquartile range] age, 60.0 [54.4-65.9] years; 5270 [52.7%] women;
7693 [77.4%] White individuals), who entered the model 100 times. The Markov model
accurately estimated the test assignment, results of anatomic and functional index
testing, referral to ICA, revascularization, MACE, and costs at 60 days and 2 years
compared with observed data in PROMISE (eg, coronary CTA: ICA, 12.2% [95% CI, 10.9%-13.5%]
vs 12.3% [95% CI, 12.2%-12.4%]; revascularization, 6.2% [95% CI, 5.5%-6.9%] vs 6.4%
[95% CI, 6.3%-6.5%]; functional strategy: ICA, 8.1% [95% CI, 7.4%-8.9%] vs 8.2% [95%
CI, 8.1%-8.3%]; revascularization, 3.2% [95% CI, 2.7%-3.7%] vs 3.3% [95% CI, 3.2%-3.4%];
2-year MACE rates: coronary CTA, 2.1% [95% CI, 1.7%-2.5%] vs 2.3% [95% CI, 2.2%-2.4%];
functional strategy, 2.2% [95% CI, 1.8%-2.6%] vs 2.4% [95% CI, 2.3%-2.4%]). Anatomic
approaches led to higher ICA and revascularization rates at 60 days, 2 years, and
5 years compared with functional testing but were more effective in patient selection
for ICA (eg, 60-day revascularization-to-ICA ratio, CTA: 53.7% [95% CI, 53.3%-54.0%];
CTA with FFRCT: 59.5% [95% CI, 59.2%-59.8%]; functional testing: 40.7% [95% CI, 40.4%-50.0%]).
Over a lifetime, anatomic approaches gained an additional 6 months in perfect health
compared with functional testing (CTA, 25.16 [95% CI, 25.14-25.19] QALYs; CTA with
FFRCT, 25.14 [95% CI, 25.12-25.17] QALYs; functional testing, 24.68 [95% CI, 24.66-24.70]
QALYs). Anatomic strategies were less costly and more effective; thus, CTA with FFRCT
dominated and CTA alone was cost-effective (ICERs ranged from $1912/QALY for women
and $3,559/QALY for men) compared with functional testing. In probabilistic sensitivity
analyses, anatomic approaches were cost-effective in more than 65% of scenarios, assuming
a willingness-to-pay threshold of $100 000/QALY. Conclusions and Relevance: The results
of this study suggest that anatomic strategies may present a more favorable initial
diagnostic option in the evaluation of low-risk SCP compared with functional testing.
