The use of lipid-lowering medication after diagnostic imaging procedures in patients with chest pain

Background

Coronary CT angiography (CTA) combined with myocardial perfusion imaging accurately detects both non-obstructive and obstructive coronary artery disease (CAD). Lipid-lowering therapy is known to effectively reduce cardiovascular events, but the impact of non-invasive imaging findings on the usage of lipid-lowering therapy remains largely unknown.

Purpose

To assess the use of lipid-lowering medication in patients referred to coronary CTA and subsequent positron emission tomography (PET) myocardial perfusion imaging due to suspected obstructive CAD.

Methods

We retrospectively analyzed data on purchases of lipid-lowering drugs obtained from the Finnish national registry for a time period starting 1 year before and ending 2 years after the date of diagnostic imaging. This time period was divided into six 6-month intervals, for each of which the presence of any statin and/or ezetimibe purchase was recorded. According to the local routine, patients with suspected obstructive (≥50%) stenosis on coronary CTA entered downstream 15O-water PET myocardial perfusion imaging during adenosine stress to assess the hemodynamic significance of the coronary stenosis. The use of medication was compared among patients with normal coronary arteries, non-obstructive CAD, and obstructive CAD.

Results

During 2008–2016, a total of 1973 patients (41% male, median age 63 years) underwent coronary CTA and 33% of these had PET perfusion imaging. There were 9081 purchases of lipid-lowering drugs during the 3-year observation period. There were 676 (34%) patients with normal coronary arteries, 640 (32%) patients with non-obstructive atherosclerosis on CTA, 325 (16%) patients with suspected obstructive stenosis on CTA but normal PET perfusion, and 332 (17%) patients with obstructive stenosis and abnormal hyperemic PET perfusion. The proportion of patients buying lipid-lowering drugs was 24%, 51%, 72%, and 91%, respectively, as assessed within the 6-month interval following the CTA/PET imaging. After diagnostic testing, proportion of patients purchasing lipid-lowering medications increased in all groups except those with normal coronary arteries (Figure 1). However, there was a marked decrease in all patient groups in proportion of patients using lipid-lowering medication towards the end of the 2-year follow-up period.

Conclusions

In a real-world cohort of symptomatic patients with chest pain undergoing diagnostic imaging for suspected CAD, subsequent purchases of lipid-lowering drugs increase in relation to the severity of imaging findings. Although majority of patients with obstructive CAD initially purchased lipid-lowering medication, our results indicate a marked decrease in the use of these preventive medications towards the end of 2-year follow-up period.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): State Research Funding of Turku University Hospital; the Academy of Finland; Finnish Foundation for Cardiovascular Research.