Practice and Outcomes of Percutaneous Coronary Intervention in the Community Before Drug-Eluting Stents: A Report from the HCA D

Rapid advancements in percutaneous coronary interventional (PCI) techniques have changed the manner in which we treat coronary artery disease.1 Clinical trials have demonstrated the efficacy of coronary stents in preventing abrupt vessel closure and restenosis, the most common adverse outcomes of PCI procedures.2–7 In addition, advancements in stent technology (flexibility, improved delivery systems and reduced profiles) have increased the number and types of lesions that can be successfully treated using stent techniques.8–9 Developments in adjuvant pharmacology, including a focus on platelet inhibition, have further improved immediate and long-term outcomes associated with PCI.10,11 Accordingly, PCI has increasingly become the first modality for myocardial revascularization in patients with both single and multivessel coronary artery disease (CAD). As such, currently there are more than 600,000 PCI procedures performed annually in the United States.12 This increase in PCI utilization has resulted in an effort to better understand the types of lesion being treated and the short-term clinical outcomes associated with PCI. A number of multi-site analyses have been reported in the literature.13–16 These studies suggest that advancements in PCI treatment have allowed the procedure to be performed on more complex lesions in older patients, while maintaining acceptable short-term outcomes. Notably, wide variations in acute outcomes are evident among different sites.16 Alternatively, randomized trials and clinical registries of novel coronary devices have established the widely accepted long-term incidence of restenosis and other adverse outcomes. However, these are most often based on select patient populations treated at a unique group of institutions. Much less is known about long-term outcomes of patients undergoing PCI in the community setting, including revascularization rates, disease progression and other adverse clinical events. The purpose of this report is to review the clinical and angiographic characteristics of patients undergoing PCI in the community setting and establish both their acute and long-term outcomes. Methods Patient population: Inclusion/exclusion. Local institutional review board (IRB) approval was obtained prior to data collection. Data were prospectively collected and analyzed on all consecutive patients undergoing a PCI procedure on native coronary arteries in the 4 community-based cardiac catheterization laboratory (CCL) sites (Appendix). Patient enrollment commenced July 1, 1999 and concluded September 30, 2000. A total of 3,192 patients were enrolled in the study; a total of 4,159 lesions were treated during the index procedure. Patients in whom the index procedure included treatment of a coronary artery bypass graft (95%) or atherectomy of any vessel (5%) were excluded. A total of 338 patients (10.8%) were excluded. Data collection. Data were obtained from 2 electronic data collection protocols routinely used by HCA hospitals as part of their quality assurance and outcomes monitoring initiative. Baseline demographic, clinical, angiographic, device use, procedural and in-lab outcome information were recorded prospectively using an ACC-NCDR-approved electronic data collection tool. All fields are defined with the approved data dictionary and the software contains internal logic to assure that all appropriate clinical information is completed for each procedure performed. Procedural lesion data include device use and type; lesion length, diameter and location; other angiographic characteristics; and success of each coronary lesion attempted. In-lab complications are defined and recorded per the ACC-NCDR standards. In-hospital procedures, complications, length of stay and cost information were obtained from the HCA Casemix Administrative database. This database includes demographic, procedural and diagnostic information on all patients hospitalized in any HCA hospital. Detailed information concerning both the CCL data collection tool and the HCA Casemix Administrative database is elsewhere in the literature.17–20 Definitions of clinical outcomes and adverse events. Angiographically successful revascularization of a lesion was defined as an absolute 20% reduction in lesion stenosis with final stenosis 24 hours without cardiac risk. Target lesion repeat PCI (TLR-PCI) was defined as a second PCI procedure within 1 year on a lesion located in the index vessel segment [22 vessel segments are defined in this study using the American College of Cardiology (ACC) standards]. Target vessel revascularization (TVR) was defined as a second PCI procedure within 1 year on a lesion located within the index vessel as defined by the ACC. Non-TLR PCI was defined as those patients having a second PCI procedure within 1 year on any vessel segment(s) other than the vessel segment(s) treated in the initial study encounter. A follow-up CABG was defined as a patient enrolled in the study who had CABG surgery during the initial hospitalization or within 1 year of the initial hospitalization. Repeat revascularization was defined as a patient enrolled in the study who had a TLR- PCI, non-TLR PCI or a follow-up CABG within 1 year of their initial study encounter. A follow-up acute myocardial infarction (AMI) was defined as any patient enrolled in the study who had a hospitalization with a primary diagnosis of AMI within 1 year of their initial study encounter. The combined major adverse cardiac events (MACE) were defined as any patient in the study who experienced at least 1 of the defined adverse events (death, repeat PCI, CABG or AMI) during the 1-year follow-up period. Study follow-up. Follow-up utilization and long-term clinical adverse events were collected using 2 sources of information. First, the 2 HCA data sets were used to prospectively determine healthcare services consumed by each patient at their initial study facility for the 1-year period following the patient’s initial PCI procedure. Follow-up utilization data were examined to determine if a patient had had a diagnostic catheterization, an additional PCI or CABG procedure, an AMI hospitalization, or died during any additional hospitalization or outpatient CCL visit during the follow-up period. Second, IRB approval was obtained from each site to survey approximately one-third of the patients enrolled in this study. This survey asked respondents to indicate if they had had an additional diagnostic catheterization procedure, any additional PCI or CABG procedures, or a hospitalization associated with an AMI at any healthcare facility during the year following their initial PCI procedure. A total of 946 surveys were completed. This paper reports long-term follow-up information based only on patients who completed the verbal survey. Statistical analysis. Discrete data are reported as the percent observed with selected characteristic, while continuous data are reported as means ± standard deviation. Differences in the observed proportion of discrete variables were compared by Chi-squared analysis or Fisher’s exact test. Differences in the mean values of continuous variables were compared by student’s t-test. All analyses were performed with SAS Version 8.2 statistical software (SAS Institute). Results Clinical demographics. Table 1 presents the baseline clinical demographic and coronary risks factors for the study patient population. A total of 62.5% were male and average patient age was 65.0 ± 12.5 years. Ninety percent of the patients were Caucasian. Over 27% of the patients enrolled in this study had already undergone at least 1 previous PCI and 13% had undergone at least 1 previous CABG. Nearly one quarter of the patients enrolled were diabetic and 25.5% had a previous MI. Procedural indications and clinical presentation. Angina was the most common reason (greater than two thirds of patients) for a patient to undergo the index PCI procedure. Of those patients with angina, the majority were unstable. For 17% of patients, the initial PCI occurred during a hospitalization with a primary diagnosis of AMI, with slightly more patients undergoing PCI for a residual lesion following an MI. A functional study indicative of myocardial ischemia was the indication for one fifth of the index PCIs. Congestive heart failure (predominantly Class I) was noted in about one fifth of the patients (Table 2). Procedure status and angiographic variables. Table 3 describes the procedure status information and angiographic variables for the initial PCI. The index revascularization procedure was overwhelmingly performed as an elective procedure (86%). The PCI procedure was more likely to be performed on de novo lesions rather than restenotic lesions (92.8% versus 6.2%, respectively). Multivessel PCI was uncommon as well; over 74% of the index procedures were performed within a single vessel. All but approximately 10% of the CCL encounters resulted in patients receiving a coronary stent (over 84% of the encounters involved coronary stents implanted in all lesions treated and approximately 6% of the encounters involved a coronary stent used in at least 1 lesion). Lesion length was similar for those patients receiving a stent and those treated only with a balloon. However, the reference vessel diameter was larger (p Lesion characteristics. Table 4 describes selected lesion characteristics for the 4,195 lesions treated in the index procedures. Treatment of very small vessels ( 3.0 mm received stents. By visual analysis, more than one-half of all lesions treated were described to have between 90–99% stenosis in the reference vessel, while an additional 10.2% of the procedures were performed on totally occluded lesions. Approximately 80% of lesions are classified as B2 or C type lesions as reported by the physician performing the procedure, suggesting commonplace treatment of complex lesions within the community. As such, lesions were long; less than one third of the lesions treated in the initial encounter were less than 10 mm. Nearly half of the lesions treated were tubular (10–20 mm) and over 18% were diffusely diseased (> 2 cm). Calcification was common, with calcification described as heavy in 7.1% and moderate in 16.9% of the lesions treated. Over 10% of the lesions treated were considered moderately angulated, while an additional 5.7% were considered extremely angulated. Finally, the tortuosity of the proximal segment was considered moderate in 10.7% of the lesions treated and extreme in 4.1%. Lesion distribution. Table 5 indicates that PCI is used to revascularize lesions in every major vessel segment in community-based practice. However, PCI of the left main remains rare, with less than 1% of procedures targeted to this site. Overall, the 3 most commonly treated lesion segment locations treated in the CCL sites included in this study were the proximal left anterior descending (LAD) coronary artery (15.6%), the mid right coronary artery (RCA) (15.5%) and the mid LAD (13.4%). Acute outcomes. Despite undertaking a substantial number of complex lesions, Table 6 indicates significant angiographic and clinical success for community-based PCI. Angiographic success (an absolute stenosis reduction of 20% with less than 50% residual stenosis without dissection, acute closure or perforation) was high, at 98%. Clinical success, as defined by angiographic success in the absence of death, MI or CABG during the index hospitalization, was also high at 93.5%. In the current era, major in-lab complications are very rare, with an incidence of in-lab death or emergent CABG of only 0.2%. The overall frequency of CABG following PCI during the initial hospitalization was slightly less than 1.1%. In-hospital mortality during the hospitalization involving the index PCI procedure was 1.5%. Long-term outcomes. MACE were common within 1 year of the index procedure in our group, with an overall 1-year event rate of 30.3%. This is summarized in Table 7. TLR with PCI at 1 year was 9.9%, with a 30-day TLR of 0.8%. TVR by PCI was 13.5% and 1.4% at 1 year and 30 days, respectively. Non-TVR PCI occurred in 13.2% and 2.8% of patients at 1 year and 30 days, respectively. In sum, a total of 24.7% of the patients had a second PCI procedure performed within 1 year. In addition, approximately 5.6% of the patients underwent CABG surgery within 1 year of their initial PCI procedure, with 1.06% occurring during the index hospitalization. Overall, a total of 27.6% of the patients in this study had at least 1 additional revascularization procedure (any PCI or CABG) within 1 year of their initial PCI. Additionally, 4.6% of patients were hospitalized for AMI during the 1-year follow-up period. Discussion The results of contemporary multicenter reports of PCI have improved our understanding of the acute outcomes associated with PCI in the stent era (between 1995 and 2000).13–16 In comparison to those treated with PTCA in the 1980s, contemporary patients undergoing a PCI procedure are older, have more extensive cardiovascular disease, and have a larger number of lesions treated in an encounter, with the procedure being more universally applied to all vessels. These reports provide an excellent snap-shot of “real world” PCI acute results from which clinicians can base their clinical decisions. However, our understanding of the long-term expected outcomes for the typical patient undergoing a PCI procedure is limited because the majority of the articles in the literature address only the initial hospital episode of care involving the PCI procedure. In addition, increasing stent usage and improved pharmacologic therapy continue to alter long-term outcomes. As a result, much less is known about long-term outcomes and information concerning disease progression associated with the typical patient undergoing PCI procedures, especially in community hospitals. Overall, the patients enrolled in this study were very similar to those reported in recent series, despite being slightly older, more likely to be female and Caucasian.10–16 In addition, the distribution of CAD risk factors, co-morbid conditions, and the proportion of patients in this study that had a prior coronary artery bypass surgery or prior PCI were similar to those reported in the ACC-NCDR study.16 The vast majority of lesions treated in this study were either B2 or C type lesions and had reference vessel diameter greater than 3.0 mm suggesting that the angiographic findings in this study are also similar to those reported in the literature. Finally, the distribution of lesions being treated by vessel location in community CCLs is nearly identical to the distribution reported in the ACC-NCDR database.16 The acute clinical results of PCI performed in this report are similar, if not favorable to those reported in the literature. For example, a total of 93.9% of the lesions treated in this analysis were reported to be treated successfully, compared to 92.2% in the ACC-NCDR database.16 Less than 1.4% percent of the patients undergoing a PCI procedure died during their initial hospitalization, which is identical to the mortality rate in the ACC-NCDR database.16 Furthermore, only 1.1% of the patients undergoing a PCI procedure also underwent CABG surgery during the same hospitalization in a community CCL, compared to 1.9% in the ACC-NCDR study.16 The lower proportion of patients undergoing CABG surgery during the index hospitalization in our study may reflect the relatively higher proportion of patients undergoing PCI with a coronary stent on a single lesion. In addition to confirming acute benchmarks, this study provides several important insights into the long-term outcomes associated with PCI procedures in the community setting. First, this study defines contemporary clinical restenosis rates for routine community-based PCI. Approximately 10% of the patients underwent repeat percutaneous intervention of the index lesion within 1 year. In approximately 10% of these cases, the second intervention occurred within 30 days, consistent with acute or subacute closure. This latter rate (1% overall) would be within the commonly accepted rate for stent thrombosis.21 Second, while the information was not available to establish the basis for post-PCI CABG in this study, we found that a total of 5.6% of patients underwent CABG within 1 year of their index procedure. Assuming that all of these cases were driven by target lesion restenosis, this would yield a clinical restenosis rate of approximately 14%. The latter assumption would be highly unlikely, however, suggesting that the 1-year clinical restenosis rate is well under 15%. Third, this study identifies a substantial incidence of clinically significant disease progression among patients undergoing PCI. Approximately 4% of patients required percutaneous revascularization in the target vessel outside the index lesion within the first year. Likewise, an additional 11.2% underwent additional PCI beyond the index vessel within the first year. Thus, slightly more (14.2% versus 9.9%) PCIs performed within 1 year were for clinically significant disease not treated during the index procedure (only 20% of these can be accounted for by staged procedure, i.e., those performed on non-target lesions within 30 days). As noted, a total of 5.6% of the patients in the study underwent CABG surgery (any vessel) within 1 year of their initial PCI procedure. In sum, 27.6% of the patients in this study had a second revascularization procedure (PCI and/or CABG) performed within 1 year of their inclusion PCI procedure. Alternatively, the event-free survival rate in this trial (freedom from death, hospitalization for MI, repeat revascularization) was approximately 70%. Study limitations. There are 2 limitations that warrant discussion. The first is that all the data in this study were self-reported, both by patients and physicians. There were no clinical or independent core lab validations of clinical or angiographic variables. However, there is a detailed set of decision rules built into the data reporting system to ensure procedure and product validation, as well as validation of data during quality reviews. In addition, this level of data validation is not different from other series, including the ACC-NCDR and SCAI reports.13–16 A second limitation is that not all patients were surveyed for long-term utilization of cardiovascular services. To examine the impact of this problem, we compared the demographic and initial cardiac risk factors of patients selected for the group surveyed versus all other enrolled patients. This analysis indicated that surveyed patients were significantly older (p Conclusion. This study validates that the patient demographics and angiographic characteristics, as well as the initial clinical outcomes of the typical patient undergoing PCI in the community setting, correlate with reports from the NCDR and other multi-site data sets. Importantly, this study provides insight into the roles that restenosis and disease progression play in the use of repeat revascularization. Drug-eluting stents carry a technologic promise to eliminate the problem of restenosis. This prospective study suggests that despite this breakthrough, community-based PCI patients will still undergo repeat revascularization at a significant rate due to disease progression and other events. While the dissemination of drug-eluting stents will represent a revolution in coronary revascularization, further improvements in secondary prevention of coronary artery disease will still be required in the future.

1. UCH Clinical Practice Advancement Center. Technology Report: Cardiac Stents. University Health System Consortium, Oak Brook, Illinois: 2000. 2. Serruys PW, de Jaeqere P, Kiemeneij F, et al. A comparison of balloon-expandable stent implantation with balloon angioplasty in patients with coronary artery disease: The BENESTENT Study Group. N Engl J Med 1994;331:489–495. 3. Fischman DL, Leon MB, Baim DS, et al., for the Stent Restenosis Study Investigators. A randomized comparison of coronary stent placement and balloon angioplasty in the treatment of coronary artery disease: Stent Restenosis Study Investigators. N Engl J Med 1994;331:496–501. 4. Buller CE, Dzavik V, Carere RG, et al. Primary stenting versus balloon angioplasty in occluded coronary arteries: The Total Occlusion Study of Canada (TOSCA). Circulation 1999;100:236–242. 5. Versaci F, Gaspardone A, Tomai F, et al. A comparison of coronary-artery stenting with angioplasty for isolated stenosis of the proximal left anterior descending coronary artery. N Engl J Med 1997;336:817–822. 6. Grines CL, Cox D, Stone GW, et al. Coronary angioplasty with or without stent implantation for acute myocardial infarction: Stent Primary Angioplasty in Myocardial Infarction Study Group. N Engl J Med 1999;341:1949–1956. 7. Doucet S, Schalij MJ, Vrolix M, et al., for the Stent In Small Arteries (SISA) Trial Investigators. Stent placement to prevent restenosis after angioplasty in small coronary arteries. Circulation 2001;104:2029–2033. 8. Kutryk M, Serruys PJ. Coronary stenting. Current Perspectives: A Companion to the Handbook of Coronary Stents. Martin Dunitz Ltd., United Kingdom: 1999. 9. Suwaidi J, Berger PB, Holmes DR. Coronary artery stents. JAMA 2000;284:1828–1836. 10. Topol EJ, Mark DB, Lincoff M, et al. Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary stenting: Results from a multicentre randomized trial. EPISTENT Investigators. Evaluation of Platelet IIb/IIIa Inhibitor for Stenting. Lancet 1999;354:2019–2024. 11. Stone GW, Grines CL, Cox DA, et al., on the behalf of the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) Investigators. Comparison of angioplasty with stenting, with or without abciximab, in acute myocardial infarction. N Engl J Med 2002;346:957–966. 12. American Heart Association. 2002 Heart and Stroke Statistical Update. Dallas, Texas: American Heart Association, 2001. 13. Laskey WK, Kimmel S, Krone RJ. Contemporary trends in coronary intervention: A report from the Registry of the Society for Cardiac Angiography and Interventions. Cathet Cardiovasc Intervent 2000;49:19–22. 14. Peterson ED, Lansky AJ, Anstrom KJ, et al. Evolving trends in interventional device use and outcomes: Results from the National Cardiovascular Network database. Am Heart J 2000;139:198–207. 15. Marks DS, Mensah GA, Kennard ED, et al. Race, baseline characteristics and clinical outcomes after coronary intervention: The New Approaches in Coronary Interventions (NACI) registry. Am Heart J 2000;140:162–169. 16. Anderson HV, Shaw RE, Brindis RG, et al., on behalf of the ACC-NCDR. A contemporary overview of percutaneous coronary interventions: The American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR). J Am Coll Cardiol 2002;39:1096–1103. 17. Heuser R, Houser F, Culler SD, et al. Do coronary stents improve clinical outcomes during the first six months following revascularization? A retrospective study of 6,671 patients comparing coronary stenting and balloon angioplasty. J Intervent Cardiol 2000;12:392–398. 18. Becker ER, Cohen D, Culler SD, et al. Benchmarking CCLoratories: The impact of patient age, gender and risk factors on variable costs, device costs and total time and procedural time in 53 catherization laboratories. J Intervent Cardiol 1999;11:533–542. 19. Cohen D, Becker ER, Culler SD, et al. Impact of patient characteristics, complications and facility volume on the cost and time of cardiac catherization and coronary angioplasty in 70 catherization laboratories. Am J Cardiol 2000;86:595–601. 20. Brown PP, Mack MJ, Simon AW, et al. Comparing clinical outcomes in high-volume and low-volume off-pump coronary bypass operation programs. Ann Thorac Surg 2001;72:S1009–S1015. 21. Leon MB, Baim DS, Popma JJ, et al. A clinical trial comparing three antithrombotic drug regimens after coronary artery stenting. Stent Anticoagulation Restenosis Study Investigators. N Engl J Med 1998;339:1665–1671.