Introduction:
Non-invasive cardiovascular imaging has been proposed as a method to improve risk stratification and motivate improved patient and physician risk factor modification. Despite increasing use of these technologies there remains limited evidence documenting its effect on downstream testing and improvement in risk factor control.
Hypothesis:
Addition of the EISNER study to a prior meta-analysis will improve statistical power to demonstrate the downstream consequences of non-invasive cardiovascular imaging.
Methods:
A comprehensive literature search of the MEDLINE database (1966 through July 2011) was conducted. Major inclusion criteria required: 1) randomized controlled trial design, 2) participants with no known history of coronary heart disease or stroke, and 3) comparison of a group provided with results of a non-invasive imaging scan versus those without results. A total of eight trials with 4,084 participants met the inclusion criteria for this analysis. We analyzed the data using a random effects model to allow for heterogeneity.
Results:
Among imaging groups there was a significant increase in prescribing for statins (RR, 1.15; 95% CI, 1.01–1.32) and a non-significant trend for increased prescription of aspirin (RR, 1.15; 95% CI, 0.97–1.35), ACE/ARB (RR, 1.12; 95% CI, 0.96–1.31), and insulin (RR, 1.54; 95% CI, 0.75–3.18). There was a non-significant trend towards increased smoking cessation (RR, 1.35; 95% CI, 0.88–2.08). For downstream outcomes there was a non-significant increase in coronary angiography (RR, 1.20; 95% CI, 0.92–1.57), but not for revascularization (RR, 0.92; 95% CI, 0.55–1.53). There was no significant effect of imaging on the change in traditional risk factors.
Limitations:
There remains a limited number of trials in this important area. Therefore, trials included in this analysis use a variety of different imaging modalities and we were not able to pool the results based on appropriate clinical action (intensification at high risk and reduction at low risk).
Conclusions:
Non-invasive cardiovascular imaging leads to increased statin use, but associations with other downstream treatments and change in risk factors are not statistically significant. Our results highlight the limited amount of data for describing the downstream consequences after CAC testing.