Clinical Outcomes in a Community-Based Single Operator Coronary Interventional Program

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1 Clinical Outcomes in a Community-Based Single Operator Coronary Interventional Program Christian J. Posner, MD, PhD; Carol L. Kaufman, RT(R) (CV) ABSTRACT Background: Physicians who perform fewer than 75 coronary interventional procedures annually and centers where fewer that 200 procedures are performed annually are considered to be low-volume and likely to have higher procedural risk and suboptimal outcomes. Methods: This was assessed in a retrospective analysis of clinical outcomes in 559 patients who underwent multi-device coronary interventions from 1994 through 2002 (prior to and during the bare metal stent era) performed by a single operator in a community hospital setting with on-site cardiac surgical services. Results: ST- and non-st-elevation myocardial infarction was present in 36.5% and 10.2% of the population, respectively, with 12.3% of ST-elevation myocardial infarction patients presenting with acute cardiogenic shock. Mortality in all patient subsets was less than 1% when patients with ST-elevation myocardial infarction and cardiogenic shock were excluded. The 6-month target lesion revascularization rate for all devices and in all patient subsets during the study period was 9.1%, and for those treated with coronary stents, the rate was 7.8%. From 1999 through 2002, the rates were 2.1% and 1.9%, respectively. Conclusions: A low-volume coronary interventional program can achieve angiographic percutaneous coronary interventional success rates and major adverse cardiac events and the need for target lesion revascularization comparable to those in high-volume major cardiac referral centers. These results were obtained even when high-risk patients with ST-elevation myocardial infarction were not excluded from the analysis. Author Affliations: Mercy Heart and Vascular Center, Janesville, Wis. Corresponding Author: Christian J. Posner, MD, PhD, Mercy Heart and Vascular Center, 1000 Mineral Point Ave, Janesville, WI 53548; phone ; fax ; cposner@ mhsjvl.org. INTRODUCTION Percutaneous coronary intervention (PCI) has been established as an effective and safe therapy for patients with coronary artery disease. The procedure has evolved from the use of balloon angioplasty in single vessel disease, and later multivessel disease, to the era of new-device angioplasty that included directional and rotational atherectomy, laser ablation, and balloon expandable stents. The introduction of drug-eluting stents in 2003 has made a significant reduction in the frequency of restenosis following coronary artery interventions. 1-2 More than 1 million coronary PCI procedures are performed in the United States annually, while the number of coronary artery bypass operations has begun to plateau. Because of the concern about suboptimal procedural outcomes, especially with low-volume operators, the recommendation has been made that individual operators should ideally perform at least 75 PCI procedures annually at high-volume centers (ie, those that perform more than 400 procedures per year). 3 The objectives of this report are to provide: (1) a retrospective analysis of the outcome of a series of consecutive patients undergoing multi-device coronary artery and coronary bypass graft interventions performed by a single operator in a community hospital with on-site cardiac surgical services, and (2) a comparison of procedural outcomes with those obtained in large centers with high-volume operators. METHODS Patient Population From 1994 through 2002, a total of 611 consecutive patients underwent PCI. Fifty-two patients treated by 2 other operators between July 1999 and December 2000 were excluded from this analysis in order to present the results of a single operator in this clinical setting. No other treated patients were excluded from the database. Patient characteristics, including age, sex, and comorbidities (diabetes, hypertension, hyper- 310

2 cholesterolemia, current or past smoking, and renal dysfunction), are presented in Table 1. Coronary artery lesion complexity was based on the American College of Cardiology/American Heart Association classification (ACC/AHA). 4 Nearly 70% of the treated lesions were type B2 or C. Patient Acuity The clinical diagnoses for patients undergoing PCI are given in Table 2. Non ST-elevation MI (NSTEMI) was present in 10.2% of the group and ST-elevation MI (STEMI) was present in 36.5% of the group with 12.3% of all STEMI patients presenting with acute cardiogenic shock (CGS). During the last 4 years of the reported series, the percentage of all patients with NSTEMI and STEMI was up to 63.7% of the annual treatment group. Intravenous thrombolytic therapy (TT) was administered to 50.5% of STEMI patients. Failed thrombolytic therapy (FTT) was the indication for rescue PCI in 56.3% of the thrombolytic treatment cohort. All patients with STEMI were transferred to the cardiac catheterization laboratory and underwent coronary arteriography and PCI either as a primary procedure or following administration of an intravenous thrombolytic agent if there was continuing angina and/or electrocardiographic evidence for residual acute injury. Those patients in whom there was elimination of angina and electrocardiographic evidence for acute injury generally underwent cardiac catheterization within hours of the acute cardiac event and comprise the STEMI/PostTT subgroup referred to in Table 2. Coronary Interventional Devices and Equipment The devices used in PCI procedures included balloons (POBA), transluminal extraction atherectomy (TEC), rotational atherectomy (ROTO), rheolytic thrombectomy (ANGIOJET), both alone and in combination with other modalities, and balloon expandable stents (STENT). Only bare metal stents were used in this patient population. All stents were deployed with balloon inflations at atmospheres for approximately 45 seconds. A second, identical balloon inflation was performed with the coronary stent delivery balloon prior to adjunctive balloon angioplasty with a high-pressure balloon. Adjunctive balloon angioplasty was not used in all patients treated with the more recent iterations of stent delivery systems unless indicated by the visual appearance of the stented segment or by intravascular ultrasound examination following stent deployment that showed incomplete stent expansion. Intravascular ultrasound (IVUS) was introduced in November 1997 and was used for assessment of lesion morphology and to plan appropriate device therapy, except Table 1. Patient Population Characteristics Percent Average age (range) 52 (31-90) Male sex 79.5 Diabetes mellitus 26.3 Hypertension 52 Hypercholesterolemia 21.3 Current/past smoking 50 Renal dysfunction 6 ACC/AHA lesion type A 13 B1 17 B2 28 C 41 Abbreviations: ACC, American College of Cardiology; AHA, American Heart Association. Table 2. Clinical Diagnoses Total Subgroup Number Percent Percent Patients 559 Elective Angina/Abn CST Unstable angina NSTEMI All STEMI STEMI STEMI/CGS STEMI/FTT STEMI/PostTT STEMI/1 PCI Abbreviations: Abn CST, abnormal cardiac stress test; CGS, cardiogenic shock; FTT, failed thrombolytic therapy; PostTT, post thrombolytic therapy; 1 PCI, primary percutaneous coronary intervention; NSTEMI, non ST-elevation myocardial infarction; STEMI, ST-elevation myocardial infarction. in patients with STEMI. The frequency distribution of coronary devices used during the study period is given in Figure 1. The procedures were conducted either percutaneously from the femoral approach or by cut-down from the brachial artery. Online quantitative coronary analysis (Siemens Quantcor) was used for measurement of vessel diameter and lesion length once it became available in the cardiac catheterization laboratory in June The use of a glycoprotein IIb/IIIa receptor inhibitor for adjunctive antiplatelet therapy in patients with STEMI and NSTEMI began in June 1996 in those patients in whom no contraindication was present. Abciximab (ReoPro) was the only IIb/IIIa inhibitor used in this patient group. Patient Follow-Up Post-procedure clinical follow-up was conducted for 96.6% of this patient population. Cardiac stress testing, 311

3 PER CENT (%) ANGIOJET IVUS POBA ROTO STENT TEC Figure 1. Coronary interventional devices: The annual frequency distribution of coronary interventional devices between 1994 and Abbreviatons: ANGIOJET, AngioJet rheolytic thrombectomy; IVUS, intravascular ultrasound; POBA, plain old balloon angioplasty; ROTO, rotational atherectomy; STENT, coronary stent; TEC, transluminal extraction atherectomy. either with stress echocardiography or nuclear imaging, was performed in 57.1% of the patients at 3 and 6 months after PCI. Diagnostic coronary arteriography was performed in 34.3% of the patients to evaluate anginal symptoms, a new clinical event, or an abnormal cardiac stress test. RESULTS Outcome Analysis Angiographic success was defined as the percentage of patients undergoing PCI in whom guiding catheter access was achieved and a guide wire and coronary device were positioned across the lesion for which treatment was planned and there was a residual stenosis of 20% and TIMI-3 flow following the procedure with no evidence for coronary artery dissection, persistent thrombus, or an undilatable lesion. Major adverse cardiac events (MACE) included mortality or emergency coronary artery bypass operation during the index hospitalization in all patients undergoing PCI. The 6-month target lesion revascularization (TLR 6 month) data was based on all patients available for clinical follow-up who underwent PCI or CABG as treatment for restenosis at the initial treatment site within 6 months of the index PCI. Procedural Outcomes Clinical outcomes for all patients in the study population and subgroups of those with NSTEMI or STEMI are presented in Table 3. Additional STEMI subgroups include patients presenting in acute cardiogenic shock (STEMI/CGS), patients with failed thrombolytic therapy who underwent rescue angioplasty (STEMI/FTT), YEAR patients treated with primary PCI (STEMI/1 PCI), and patients treated with coronary stents (STEMI/STENT). The patients with STEMI/CGS were responsible for 71.4% (10 of 14 patients) of the overall mortality reported in all STEMI subgroups. There was no mortality in elective patients with any interventional device including coronary stents or in STEMI patients treated with 1 PCI. Mortality in all patient subsets was less than 1% when patients with STEMI and cardiogenic shock were excluded. MACE in the STEMI/1 PCI subgroup represented 2 patients who underwent emergency CABG, and in the STEMI/FTT subgroup there was 1 mortality. The TLR 6-month rate for all devices and in all patient subsets during the study period was 9.1%. The TLR 6-month rate in all STEMI subgroups was lower when compared with elective patients. Outcome data for elective, NSTEMI and STEMI patients treated with coronary stents are given in Table 4. No MACE occurred in elective patients. NSTEMI and STEMI patients receiving coronary stents had a lower MACE rate compared with all patients in the study group. The TLR 6-month rate in the group of all stent-treated patients was lower than in the entire study population. There was no difference in the average number of stents deployed per patient in the elective, NSTEMI or STEMI subgroups (1.4 stents/patient). The outcomes of all patients receiving abciximab and those in the subgroups of STEMI/1 PCI, STEMI/FTT, NSTEMI/STENT, and STEMI/STENT are given in Table 5. A total of 416 patients in the entire study group underwent coronary interventional procedures after abciximab received FDA approval in This was administered to 32% of eligible NSTEMI and 52.6% of eligible STEMI patients, as well as 9.3% of eligible elective patients (see Table 3). No MACE or TLR 6-month were reported in the STEMI/1 PCI or STEMI/FTT patient subgroups treated with abciximab. The MACE and TLR 6-month data for each year during the study period are presented in Table 6. Both MACE and TLR 6-month were very low during the 4-year period of , with a TLR 6-month of 2.1% for all patients for this time interval and 1.9% for patients receiving coronary stents. The percentage of all patients with NSTEMI and STEMI in this 4-year period was up to 63.7% of the total annual treatment group compared with 46.7% over the entire study period. In 2001, the reported MACE in the total patient population was due to 1 patient who had emergency repeat CABG after failure to successfully treat a high-grade stenosis at the distal anastomosis of a fresh coronary graft to a coronary artery supplying critical myocardial blood flow. 312

4 Table 3. Patient Outcomes Total - STEMI- Total STEMI/CGS Elective NSTEMI STEMI STEMI/CGS STEMI/CGS Patients Angiographic Success (%) IIb/IIIa Inhibitor (%) MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) STEMI/ Elective STEMI/ PCI STEMI/FTT STENT STENT ACC-NCDR SCA&I Duke (BMS) Patients Angiographic Success (%) IIb/IIIa Inhibitor (%) MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) Abbreviations: ACC-NCDR, American College of Cardiology-National Cardiovascular Data Registry; AMI, acute myocardial infarction; CABG, coronary artery bypass graft; CGS, cardiogenic shock; FTT, failed thrombolytic therapy; MACE, major adverse cardiac events; PTCA, percutaneous transluminal coronary angioplasty; Q-Wave MI, Q-Wave myocardial infarction; SCA&I, Society for Cardiac Angiography & Interventions; TLR, target lesion revascularization. TLR 6-month in the total and stent treatment populations was due to 1 other patient who had successful treatment for in-stent restenosis. In 2002, MACE was due to 2 patients who presented with STEMI/CGS and expired following PCI using coronary stents. DISCUSSION This report presents data from a patient population with a relatively large number of those with STEMI and rescue PCI following failed thrombolytic therapy. This may be related to the prevalence of coronary heart disease in the population served by the community hospital from which this data originates. The average annual mortality related to coronary heart disease was 43.8% for the period and 40.5% in 1994 for Rock County, Wisconsin, where the hospital is located. 5 The small total patient volume is in part a function of the more rural location of treatment services and the geographic proximity to large referral centers located within a 60-minute drive. The intention was to perform primary PCI in all patients with STEMI. Facilitated PCI with pre-procedural administration of intravenous thrombolytic therapy was used when there were mitigating clinical circumstances at the time of presentation such as severe angina in the set- Table 4. Patient Outcomes: Coronary Stents Total Elective NSTEMI STEMI Patients Angiographic Success (%) IIb/IIIa Inhibitor (%) MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) Abbreviations: CABG, coronary artery bypass graft; IIb/IIIa inhibitor, glycoprotein IIb/IIIa receptor inhibitor (abciximab); MACE, major adverse cardiac events; PCI, percutaneous coronary intervention; STEMI, ST-elevation myocardial infarction; NSTEMI, non ST-elevation myocardial infarction; TLR 6 mo, target lesion revascularization at 6 months. ting of dramatic electrocardiographic evidence for acute injury, hemodynamic instability or a weather-related time delay in transport from a nearby facility. It was therefore not always possible to determine which patients in the failed thrombolytic therapy subset would initially have been selected for a primary PCI procedure. Despite the low-volume character of the interventional program, clinical outcomes were comparable to that reported in the American College of Cardiology-National 313

5 Table 5. Patient Outcomes: IIb/IIIa Receptor Inhibition with abciximab Total STEMI/ 1 PCI STEMI/FTT NSTEMI/STENT STEMI/STENT Patients Angiographic Success (%) IIb/IIIa Inhibitor (%) MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) Abbreviations: IIb/IIIa inhibitor, glycoprotein IIb/IIIa receptor inhibitor (abciximab); CABG, coronary artery bypass graft; FTT, failed thrombolytic therapy; MACE, major adverse cardiac event; PCI, percutaneous coronary intervention; STEMI, ST-elevation myocardial infarction; NSTEMI, non ST-elevation myocardial infarction; TLR 6 mo, target lesion revascularization at 6 months. Table 6. Annual MACE and TLR Data ACC-NCDR SCA&I Duke (BMS) Total Patient Population 38 a 71 a 85 a 80 a 82 a 51 a 42 a 53 a 57 a 100,292 19,510 MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) Stent Patient Population 0 b 10 b 40 b 38 b 58 b 28 b 38 b 48 b 50 b 3165 MACE (%) Mortality (%) CABG (%) TLR 6 mo (%) PCI (%) CABG (%) a N=559 b N=310 Abbreviations: ACC-NCDR, American College of Cardiology-National Cardiovascular Data Registry; BMS, bare metal stent; CABG, coronary artery bypass graft; CGS, cardiogenic shock; Duke, Duke Databank for Cardiovascular Disease; MACE, major adverse cardiac events; PCI, percutaneous coronary intervention; SCA&I, Society for Cardiac Angiography & Interventions Registry; TLR 6 mo, target lesion revascularization at 6 months; NSTEMI, non ST-elevation myocardial infarction; STEMI, ST-elevation myocardial infarction. Cardiovascular Data Registry (ACC-NCDR) and the Society for Cardiac Angiography and Interventions registry (see Tables 3 and 6). 6-7 In the ACC-NCDR registry, PCI for STEMI less than 6 hours from symptom onset was performed in 10% of the reported procedures. 6 In the SCAI Registry, intervention for STEMI less than 24 hours from symptom onset was performed in 8.5% of the reported procedures, 75.1% of the procedures were elective, and the majority of lesions were ACC/AHA type B (66.4 %) with type A present in 17% and type C present in 17%. 7 Data from patients with STEMI and cardiogenic shock were not reported in either registry. When outcomes were studied in a large clinical database from an academic practice setting (Duke Databank for Cardiovascular Disease), the TLR 6-month was 9.6% for bare metal stents and 2.6% for drug-eluting stents. 8 The factors most likely to explain the reduction in MACE and TLR 6-month rates over the reported study period are the availability of coronary stents and the introduction of IIb/IIIa inhibitors, particularly when used in patients with STEMI. The use of intravascular ultrasound for pre-procedural evaluation of lesion morphology and optimal selection of treatment strategy has been advocated since angiography alone may be ambiguous. 9 In the current report, IVUS was used in every procedure from late 1997 through the end of 2000 if technically feasible unless STEMI was present. There was a temporal correlation with the use of this technology and the subsequent reduction in adverse clinical outcomes based upon MACE and TLR 6-month data (Table 6) 314

6 emphasizing the importance of achieving optimal stent expansion for excellent long term clinical outcomes. After 2000, visual assessment of the angiographic result tended to supplant IVUS with a sustained reduction in MACE and TLR 6-month over the next 2 years, suggesting a possible role of experience with IVUS in the subsequent recalibration of an operator s visual assessment of angiographic images. The Case for Bare Metal Stents The introduction of drug-eluting stents (DES) has resulted in a reduction in the need for treatment of instent restenosis. However, there is a small but measurable higher incidence of late and very late subacute thrombosis (SAT) with these devices. 10 This has prompted recommendation of a longer duration of dual antiplatelet therapy (DAT) for patients receiving DES compared with bare metal stents (BMS). 11 As a consequence of the significant morbidity and mortality associated with SAT, the suggestion has been made to carefully consider the use of DES in certain high-risk patient subsets. 12 The longer duration of DAT and the risk of discontinuing DAT have wide implications for patients who need to undergo surgery or other invasive procedures. A DES that is more effective at preventing restenosis must be required to be very similar or better than BMS in terms of frequency of SAT for a net advantage to exist. 13 While multiple factors are likely to be responsible for the observed late and very late SAT, there is a clear mandate for impeccable interventional technique especially with DES deployment. The present data show that the MACE and TLR 6- month rates for coronary interventions performed with BMS can be extremely low in both elective procedures and also those performed in high-risk patients with acute coronary syndromes (NSTEMI and STEMI). This supports a compelling need to carefully reexamine the risks and benefits of the use of current generation DES and to consider the use of BMS in some patient subsets. CONCLUSIONS Clinical outcomes as determined by parameters of angiographic success, major adverse cardiac event rates, and the need for target lesion revascularization in a low-volume coronary interventional program can be comparable to accepted standards of care based on data from national registries that generally represent outcomes obtained in high-volume programs in major cardiac referral centers. The data presented show that MACE and TLR 6-month rates for coronary interventions performed with BMS are extremely low in patients with high lesion complexity in both elective procedures and those performed in patients with acute coronary syndromes (both NSTEMI and STEMI). It is imperative to carefully examine the risks and benefits of the use of current generation DES in all subsets of patients. Acknowledgments: The authors wish to acknowledge the excellent patient care and technical expertise provided by all of the past and present members of the cardiac catheterization laboratory staff at Mercy Hospital in Janesville, Wis. Funding/Support: None declared. Financial Disclosures: None declared. References 1. Urban P, Gershlick AH, Guagliumi G, et al., on behalf of the e-cypher Investigators. Safety of coronary sirolimus-eluting stents in daily clinical practice: one-year follow-up of the e-cypher Registry. Circulation. 2006;113: Goy JJ, Stauffer JC, Siegenthaler M, et al. A prospective randomized comparison between paclitaxel and sirolimus stents in the real world of interventional cardiology: the TAXi trial. J Am Coll Cardiol. 2005;45: Smith SC, Feldman TE, Hirshfield JW, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). Circulation. 2006;113:e1- e Ellis SG, Vandormael MG, Crowley MJ, et al. Coronary morphologic and clinical determinants of procedural outcome with angioplasty for multivessel disease: implications for patient selection. Circulation. 1990;82: Wisconsin Department of Health and Family Services, Division of Health, Center for Health Statistics People with Chronic Conditions Community Health Profiles Rock County. Madison, WI: pdf/chronic/rock.pdf. Accessed on August 20, Anderson HV, Shaw RE, Brindis RG, et al. A contemporary overview of percutaneous coronary interventions. the American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR ). J Am Coll Cardiol. 2002;39: Laskey WK, Kimel 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: Angstrom KJ, Kong DF, Shaw LK, et al. Long-term clinical outcomes following coronary stenting. Arch Intern Med. 2008;168: Mintz GS, Popma JJ, Pichard AD, et al. Limitations of angiography in the assessment of plaque distribution in coronary artery disease. Circulation. 1996;93: Bavry AA, Cuban DJ, Helton TJ, et al. Late thrombosis of drugeluting stents: a meta-analysis of randomized clinical trials. Am J Med. 2006;119: King SB, Smith SC, Hirshfeld, JW, et al focused update of the ACC/AHA/SCAI guideline update for percutaneous coronary intervention. a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. Circulation. 2008;117: Slottow TLP, Steinberg DH, Roy PK, et al. Observations and outcomes of definite and probable drug-eluting stent thrombosis seen at a single hospital in a four-year period. Am J Cardiol. 2008;102: Garg P, Cohen DJ, Gaziano T, et al. Balancing the risks of restenosis and stent thrombosis in bare-metal versus drug-eluting stents. J Am Coll Cardiol. 2008;51:

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