Clinical and economic burden associated with cardiovascular events among patients with hyperlipidemia: a retrospective cohort study

Abstract

Background: Annual direct costs for cardiovascular (CV) diseases in the United States are approximately $195.6 billion, with many high-risk patients remaining at risk for major cardiovascular events (CVE). This study evaluated the direct clinical and economic burden associated with new CVE up to 3 years post-event among patients with hyperlipidemia.

Methods: Hyperlipidemic patients with a primary inpatient claim for new CVE (myocardial infarction, unstable angina, ischemic stroke, transient ischemic attack, coronary artery bypass graft, percutaneous coronary intervention and heart failure) were identified using IMS LifeLink PharMetrics Plus data from January 1, 2006 through June 30, 2012. Patients were stratified by CV risk into history of CVE, modified coronary heart disease risk equivalent, moderate- and low-risk cohorts. Of the eligible patients, propensity score matched 243,640 patients with or without new CVE were included to compare healthcare resource utilization and direct costs ranging from the acute (1-month) phase through 3 years post-CVE date (follow-up period).

Results: Myocardial infarction was the most common CVE in all the risk cohorts. During the acute phase, among patients with new CVE, the average incremental inpatient length of stay and incremental costs ranged from 4.4-6.2 days and $25,666-$30,321, respectively. Acute-phase incremental costs accounted for 61-75% of first-year costs, but incremental costs also remained high during years 2 and 3 post-CVE.

Conclusions: Among hyperlipidemic patients with new CVE, healthcare utilization and costs incurred were significantly higher than for those without CVE during the acute phase, and remained higher up to 3 years post-event, across all risk cohorts.

Fig. 1

Patient Selection Flowchart. *Propensity score matching was applied for each cardiovascular disease risk cohort using covariates: age group, gender, US region, baseline Charlson comorbidity index score, Chronic Disease Score, comorbidities and number of inpatient admissions per patient per month. CV: cardiovascular; CHD RE: coronary heart disease risk equivalent; PSM: propensity score matching

Fig. 2

PSM-adjusted Distribution of Index CV Event According to CVD Risk Level. CV: cardiovascular; CVD: cardiovascular disease; PSM: propensity score matching; MI: myocardial infarction; UA: unstable angina; IS: ischemic stroke; CABG: coronary artery bypass graft; PCI: percutaneous coronary intervention; HF: heart failure; TIA: transient ischemic attack; CHD RE: coronary heart disease risk equivalent