- In this case–control study, subclinical atherosclerosis found on coronary computed tomography angiography (CCTA) was associated with increased likelihood of subsequent statin prescription and persistently lower LDL cholesterol levels
- Still, one in three individuals with subclinical atherosclerosis who were at intermediate to high risk of atherosclerotic cardiovascular disease remained without statins, even though >90% saw a physician within six months of abnormal CCTA
- Many patients who had both elevated risk of atherosclerotic cardiovascular disease (based on clinical risk factors) and subclinical atherosclerosis on CCTA did not receive recommended preventive therapy
Increasingly often, coronary computed tomography angiography (CCTA) is being used in emergency departments to evaluate patients with acute chest pain. In randomized, controlled trials, about 50% of individuals undergoing CCTA in this setting have been found to have nonobstructive coronary artery disease (CAD).
Michael Honigberg, MD, MPP, cardiology fellow, and Pradeep Natarajan, MD, MMSc, director of the Cardiovascular Disease Prevention Center at Massachusetts General Hospital, in collaboration with Udo Hoffmann, MD, MPH, and Brian Ghoshhajra, MD, MBA of the Division of Cardiovascular Imaging, and colleagues have found that opportunistic detection of nonobstructive CAD often prompts inpatient or outpatient physicians to initiate statins. However, as they report in JACC: Cardiovascular Imaging, too many of these patients receive suboptimal follow-up care.
The researchers studied 510 patients found to have nonobstructive CAD (i.e., classification of 1 or 2 on the Coronary Artery Disease Reporting and Data System) that underwent CCTA for evaluation of acute chest pain or possible acute coronary syndrome in the emergency department at Mass General between November 1, 2013, and March 31, 2018. They were matched against 510 control patients not found to have CAD who were matched to the cases by age and sex.
To ensure an accurate assessment of subsequent management, patients had to be receiving primary care at the hospital or establish a primary care relationship within six months. The patients were followed until March 31, 2018 or six months after CCTA, whichever came first.
Primary Outcome: Statin Prescriptions
- After CCTA, the prevalence of statin prescriptions increased significantly among both cases (from 39% to 56%, a 44% relative increase). On multivariate analysis, CAD patients had a 7.1-fold increase in the likelihood of statin prescription (95% CI, 4.4–23.0; P < .001)
- Statin therapy was newly initiated in significantly more CAD cases than controls (18% vs. 3%)
- Among patients already taking statins, the statin dose was increased for significantly more CAD cases than controls (7% vs. 2%)
At the end of follow-up, 30% of the 70 CAD cases at high 10-year risk of atherosclerotic cardiovascular disease (ASCVD) and 33% of the 174 CAD cases at intermediate risk were not receiving a statin. This was true even though 90% of CAD cases saw a primary care provider and/or a cardiologist for an outpatient examination within six months of CCTA.
Another concern is that after CCTA, the prevalence of statin prescriptions for controls (proven not to have CAD) actually increased significantly, from 18% to 20%. Moreover, 15% of controls with low 10-year ASCVD risk (<5%) were prescribed statins after CCTA.
Change in LDL-C
At baseline, there was no significant difference between cases and controls in average LDL-C levels. At an average of 1.9 years after CCTA, the average LDL-C level was significantly lower in CAD cases than in controls (102 vs. 117 mg/dL). That difference was affirmed in a multivariate analysis that was adjusted for age, sex and baseline LDL-C.
Additional Preventive Measures
- During follow-up, there was no initiation or dose change of non-statin cholesterol-lowering medications. No patients were prescribed a PCSK9 inhibitor
- Aspirin prescriptions increased significantly among both cases and controls. Cases had a significant four-fold increased likelihood of aspirin prescription compared with controls
- Only 9% of patients with body mass index ≥35 kg/m2 were referred to a nutritionist within six months
- Only 33% of cases who were current smokers were prescribed pharmacotherapy for smoking cessation or were referred for a smoking cessation consultation
Opportunities to Improve Follow-up Care
The researchers state that a coronary artery calcium score of zero from CCTA performed in the emergency department could be used to consider statin de-escalation in nonsmoking patients with low ASCVD risk (<5%). They estimated ASCVD risk using the American Heart Association pooled cohort equations and associated calculator.
The role of aspirin in primary prevention of cardiovascular events has been called into question by recent trials (published after the present study period). Clinicians should be aware that the 2019 American College of Cardiology/American Heart Association guidelines for primary prevention, as published in Circulation, downgrade the role of aspirin. Dedicated studies will be needed to show whether aspirin is efficacious among a subset of patients with subclinical coronary atherosclerosis who are already using statins.
Without a protocol and systemic supports in place, preventive medicines for patients with nonobstructive CAD may not be initiated or escalated. A reporting system that harmonizes the emergency department and outpatient workflows would ideally integrate clinical ASCVD risk scores and radiographic findings.
In this study, consultation with a cardiologist was an independent predictor of statin prescription for patients with nonobstructive CAD. As previously reported by other Mass General cardiologists in the JACC, remote consultation (e-consultation) may improve access to cardiology care.
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