Abstract P374: Incidence and Costs of Cardiovascular Events among High Risk Patients with Hyperlipidemia
Authors: Bonafede Machaon M , Johnson Barbara H , Richhariya Akshara , Gandra Shravanthi R 
Published: July 2021

Background:
Advances in cardiovascular (CV) disease management have reduced acute CV event risk; however, the burden of these events remains substantial. We identified a cohort of high risk coronary heart disease risk equivalent patients to examine the incidence of subsequent inpatient CV events and cost of first, subsequent and fatal inpatient CV events.

Methods:
The Truven Health MarketScan® Commercial Database was used to identify adults with hyperlipidemia or lipid-lowering therapy in the 18 months prior to one of the following new inpatient CV events: myocardial infarction (MI), ischemic stroke, unstable angina (UA), revascularization without MI, UA, or stroke (coronary artery bypass graft [CABG] or percutaneous coronary intervention [PCI]), or heart failure between 2006 and 2012. Patients were required to have a pre-index diagnosis of peripheral arterial disease, abdominal aortic aneurysm, carotid artery disease or diabetes (CHD RE). Direct medical costs were reported for each three-month quarter following a CV event, for up to 36 months after the first CV event. Fatal CV events were identified for a subset of patients with Social Security Administration Master Death File (SSAMDF) data to determine presence of death within 90 days of a CV event.

Results:
A total of 38,609 CHD RE patients met the study criteria (mean age 57 years, 69% male). CABG, MI and PCI were the most frequent and most expensive first CV events, accounting for >75% of all first CV events. Mean quarter 1 (Q1) non-fatal and fatal direct costs were highest for CABG ($77,701 and $125,690), followed by MI ($47,869 and $56,577) and PCI ($38,744 and $64,387). First event stroke, TIA and UA mean Q1 direct costs ranged from a low of $17,454 (non-fatal TIA) to a high of $72,449 (fatal UA). Overall, 15% of those with a first CV event went on to have a second event during the 36 month study period, with an average time to event of 217 days. Of patients with SSAMDF availability, 1.8% of acute CV events were fatal (range 1-4% by event type) and average Q1 costs for fatal events were 1.5 times higher than average costs for non-fatal events (range 1.2-5.5 times). Overall, 2.8% of patients went on to have a third acute CV event, occurring on average 230 days following the second event. Mean quarterly costs in Q2 drop substantially to between 8.2% (CABG) and 33.6% (TIA) of Q1 event costs. Average quarterly costs stabilized at approximately 1.4 times higher than average pre-event costs for Q3 through Q12; costs never returned to pre-event levels.

Conclusions:
MI was the most common first inpatient CV event in high risk CHD RE patients. Recurrent CV events are common and occur, on average, within 8 months. CV events were costly, regardless of sequence, averaging $47,433 in the first 90 days following an event. During the follow-up period, costs never returned to their pre-event levels. Though uncommon, fatal CV events have substantially higher costs than non-fatal events.