Study Quantifies Costs Arising From Thrombotic Events During PCI for NSTE-ACS

Thrombotic events that occur during PCI in patients with NSTE-ACS raise both in-hospital and 30-day costs by approximately 20%, according to a subanalysis of the ACUITY trial published online March 25, 2015, ahead of print in Catheterization and Cardiovascular Interventions.

Out of the nearly 14,000 trial participants, researchers led by Gregg W. Stone, MD, of Columbia University Medical Center (New York, NY), looked at a subset of 1,307 who underwent PCI in United States and had both angiographic core lab and economic data. Medical costs were estimated using 2005 prices and then converted to 2012 US dollars.

Within the final study population, 52 patients (4.0%) experienced thrombotic events during the index PCI: 28 had slow reflow, 17 had distal thromboemboli, 15 had acute vessel closure, 10 had new or progressive thrombus, 8 had no reflow, 6 had side branch closure, and 5 had stent thrombosis (of whom 3 experienced MI, 2 developed major bleeding, and 1 required unplanned PCI revascularization). A total of 21 patients had more than 1 intraprocedural thrombotic event.

At baseline, patients with events were less likely to have hyperlipidemia, previous PCI, and prior use of statins and ACE inhibitors/angiotensin receptor blockers than those without events. They also had elevated cardiac biomarkers and white blood cell counts; were more likely to have TIMI grade flow of 0 or 1; and tended to have larger reference vessel diameter, smaller minimal lumen diameter, and higher percent vessel stenosis and incidence of total occlusion.

Thrombotic events during PCI were associated with longer procedures (mean 54.9 vs 32.4 minutes) and lengths of stay (mean 4.6 vs 2.7 days; P < .001 for both).

Median in-hospital and 30-day costs were higher for patients with intraprocedural thrombotic events than for those without the complication (table 1).

 

Modeling was performed to account for cost distributions being heavily right-skewed and for differences in clinical and angiographic characteristics. After adjustment, occurrence of thrombotic events during PCI was associated with cost increases of 19.5% in the hospital and 18.9% at 30 days, representing absolute differences of $3,592 and $3,696, respectively.

“With ~300,000 ACS PCI procedures each year in the United States, these findings suggest that [intraprocedural thrombotic events] may cost the US healthcare system ~$38 million/year,” Dr. Stone and colleagues stress. “Thus, identifying strategies to reduce [the complications] may substantially reduce healthcare expenditures as well as avoid serious adverse events.”

The question, they say, is what can be done. Baseline cardiac biomarker elevation and lack of hyperlipidemia have both been associated with increased risk but “cannot be modified in an acute setting immediately before PCI,” the researchers point out. “[C]lopidogrel requires gastric absorption and conversion to active metabolite by the liver, which varies by genotype and other factors. Ticagrelor [Brilinta; AstraZeneca] and prasugrel [Effient; Eli Lilly/Daiichi Sankyo] are novel oral P2Y12 receptor inhibitors [that] are less affected by genetic factors but [that] also have delayed absorption and onset when used in the acute setting.”

Another option, they suggest, is cangrelor; the intravenous ADP antagonist under development by The Medicines Company was shown in CHAMPION PHOENIX to reduce the risk of stent thrombosis during PCI.

Dr. Stone and colleagues acknowledge that the current results may not extend to patients undergoing PCI for stable angina or STEMI. They also cite several limitations to the study, including its “fairly homogenous population” and clinical trial rather than real-world setting.

Note: Dr. Stone and several coauthors are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD. 

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Source:
Plent S, Fan W, Kirtane A, et al. Cost implications of intraprocedural thrombotic events during PCI. Catheter Cardiovasc Interv 2015;Epub ahead of print.

Disclosures:

• The study was funded by The Medicines Company.
• Dr. Stone reports no relevant conflicts of interest.

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