PCI Trends and Impact; Costs of New Devices Studied

May 4, 2011—In the Journal of the American Medical Association (JAMA), Andrew J. Epstein, PhD, Peter W. Groeneveld, MD, et al published a study of coronary revascularization trends in the United States from 2001 to 2008 (2011;305:1769–1776). On April 25, Drs. Epstein, Groeneveld, et al published research online ahead of print in the Archives of Internal Medicine that evaluated the impact of new cardiovascular device technology on health care cost.

In the JAMA study, the investigators concluded that in hospitals in the United States between 2001 and 2008, a substantial decrease in coronary artery bypass graft (CABG) surgery utilization rates was observed, but percutaneous coronary interventions (PCIs) utilization rates remained unchanged.

According to the investigators, coronary revascularization is among the most common hospital-based major interventional procedures performed in the United States. It is uncertain how new revascularization technologies, new clinical evidence from trials, and updated clinical guidelines have influenced the volume and distribution of coronary revascularizations over the past decade. This study was then conducted to examine national time trends in the rates and types of coronary revascularizations.

According to JAMA, the study was a serial cross-sectional study with time trends of patients undergoing CABG surgery or PCI between 2001 and 2008 at United States hospitals in the Healthcare Cost and Utilization Project's Nationwide Inpatient Sample, which reports inpatient coronary revascularizations. These data were supplemented by Medicare outpatient hospital claims. The main outcome measures are annual procedure rates of coronary revascularizations, CABG surgery, and PCI.

The investigators reported that a 15% decrease (P < .001) in the annual rate of coronary revascularizations was observed from 2001–2002 to 2007–2008. The annual CABG surgery rate decreased steadily from 1,742 (95% confidence interval [CI], 1,663–1,825) CABG surgeries per million adults per year in 2001–2002 to 1,081 (95% CI, 1,032–1,133) CABG surgeries per million adults per year in 2007 to 2008 (P < .001), but PCI rates did not significantly change (3,827 [95% CI, 3,578–4,092] PCI per million adults per year in 2001–2002 vs 3,667 [95% CI, 3,429–3,922] PCI per million adults per year in 2007–2008; P = .74).

Between 2001 and 2008, the number of hospitals in the Nationwide Inpatient Sample providing CABG surgery increased by 12% (212 in 2001 vs 241 in 2008; P = .03), and the number of PCI hospitals increased by 26% (246 in 2001 vs 331 in 2008; P < .001). The median CABG surgery caseload per hospital decreased by 28% (median [interquartile range], 253 [161–458] in 2001 vs 183 [98–292] in 2008; P < .001) and the number of CABG surgery hospitals providing fewer than 100 CABG surgeries per year increased from 23 (11%) in 2001 to 62 (26%) in 2008 (P < .001), the investigators found.

On April 25, Drs. Epstein, Groeneveld, et al published research online ahead of print in the Archives of Internal Medicine that evaluated the impact of new cardiovascular device technology on health care cost. The investigators sought to assess the overall impact of drug-eluting stents (DES) on Medicare expenditures in a nationally representative cohort of Medicare beneficiaries with coronary artery disease (CAD).

The investigators found that between 2002 and 2006 DES coronary stents, which were introduced in 2003, added $1.57 billion in annual Medicare expenditures among beneficiaries aged 66 to 85 years, with the largest cost increase occurring among patients without acute coronary syndrome (ACS).

As detailed in the Archives of Internal Medicine, the investigators calculated mean annual payer-perspective costs among patients with CAD during 2002 through 2006 (including 2002 costs as a baseline), in each US Hospital Referral Region (HRR) using a 5% random sample of fee-for-service Medicare beneficiaries, excluding patients younger than 66 years and older than 85 years, when DES use declines markedly at older ages).

Calculations were separately performed on each of three CAD subcohorts categorized annually by clinical events: patients with acute myocardial infarction (AMI), patients with ACS but no AMI, and patients without ACS.

The investigators reported that calculations were derived from 1,981,088 Medicare beneficiaries with CAD, of whom 4.5% had a recent AMI, 3.4% had a recent noninfarction ACS, and 92% had no recent ACS. Between 2002 and 2006, DES use increased from 0% in all subcohorts to 23% among patients with AMI, 29% among patients with noninfarction ACS, and 1.1% among patients without ACS. Inflation-adjusted cost increases during 2002 through 2006 among CAD subcohorts ranged from 4.7% to 11.7%.

According to the investigators, multivariable regressions indicated that each 1% increase in DES use was associated with a $28 mean per-patient cost increase (P = .009) among patients with AMI, a $35 increase (P < .001) among patients with noninfarct ACS, and a $133 increase (P = .003) among patients without ACS. These estimates implied a DES-attributable increase in annual expenditures on patients with AMI of $657, on patients with noninfarct ACS of $999, and on patients without ACS of $146. Because most patients with CAD were non-ACS cases, this subgroup composed the largest portion of DES-attributable national cost growth.

The investigators commented that coronary DES substantially increased costs for Medicare beneficiaries with CAD. The fraction of DES cost growth attributable to patients without ACS (68%) was much larger than the proportion of DES received by this subcohort (33%), suggesting that DES use among patients without ACS was particularly cost amplifying (ie, DES introduction changed patterns of care for patients without ACS in a more costly manner than for patients with ACS). This is troubling, the investigators said, because the limited efficacy of PCI among patients with ACS, whether or not DES are used, would not justify sizeable DES-related cost increases among patients without ACS.

The investigators noted that this observational study could not establish whether the association between increased DES use and cost growth was causal. They acknowledged that use of DES may be appropriate in selected patients without ACS and could deliver benefits at an acceptable cost. Outpatient pharmaceutical costs were not included; these may have amplified or attenuated the DES-associated cost increase, the investigators advised.

In an accompanying commentary to the study, Rita F. Redberg, MD, Chief Editor of the Archives of Internal Medicine, stated, “It is time to clearly define what the value of this extraordinary investment has been in terms of patient benefits and study the harms and determine if we are getting good value for this outlay.”