Richard E. Shaw

Comparative Effectiveness of Revascularization Strategies

BACKGROUND Questions persist concerning the comparative effectiveness of percutaneous coronary intervention (PCI) and coronary-artery bypass grafting (CABG). The American College of Cardiology Foundation (ACCF) and the Society of Thoracic Surgeons (STS) collaborated to compare the rates of long-term survival after PCI and CABG. METHODS We linked the ACCF National Cardiovascular Data Registry and the STS Adult Cardiac Surgery Database to claims data from the Centers for Medicare and Medicaid Services for the years 2004 through 2008. Outcomes were compared with the use of propensity scores and inverse-probability-weighting adjustment to reduce treatment-selection bias. RESULTS Among patients 65 years of age or older who had two-vessel or three-vessel coronary artery disease without acute myocardial infarction, 86,244 underwent CABG and 103,549 underwent PCI. The median follow-up period was 2.67 years. At 1 year, there was no significant difference in adjusted mortality between the groups (6.24% in the CABG group as compared with 6.55% in the PCI group; risk ratio, 0.95; 95% confidence interval [CI], 0.90 to 1.00). At 4 years, there was lower mortality with CABG than with PCI (16.4% vs. 20.8%; risk ratio, 0.79; 95% CI, 0.76 to 0.82). Similar results were noted in multiple subgroups and with the use of several different analytic methods. Residual confounding was assessed by means of a sensitivity analysis. CONCLUSIONS In this observational study, we found that, among older patients with multivessel coronary disease that did not require emergency treatment, there was a long-term survival advantage among patients who underwent CABG as compared with patients who underwent PCI. (Funded by the National Heart, Lung, and Blood Institute.).

Contemporary mortality risk prediction for percutaneous coronary intervention: results from 588,398 procedures in the National Cardiovascular Data Registry.

OBJECTIVES We sought to create contemporary models for predicting mortality risk following percutaneous coronary intervention (PCI). BACKGROUND There is a need to identify PCI risk factors and accurately quantify procedural risks to facilitate comparative effectiveness research, provider comparisons, and informed patient decision making. METHODS Data from 181,775 procedures performed from January 2004 to March 2006 were used to develop risk models based on pre-procedural and/or angiographic factors using logistic regression. These models were independently evaluated in 2 validation cohorts: contemporary (n = 121,183, January 2004 to March 2006) and prospective (n = 285,440, March 2006 to March 2007). RESULTS Overall, PCI in-hospital mortality was 1.27%, ranging from 0.65% in elective PCI to 4.81% in ST-segment elevation myocardial infarction patients. Multiple pre-procedural clinical factors were significantly associated with in-hospital mortality. Angiographic variables provided only modest incremental information to pre-procedural risk assessments. The overall National Cardiovascular Data Registry (NCDR) model, as well as a simplified NCDR risk score (based on 8 key pre-procedure factors), had excellent discrimination (c-index: 0.93 and 0.91, respectively). Discrimination and calibration of both risk tools were retained among specific patient subgroups, in the validation samples, and when used to estimate 30-day mortality rates among Medicare patients. CONCLUSIONS Risks for early mortality following PCI can be accurately predicted in contemporary practice. Incorporation of such risk tools should facilitate research, clinical decisions, and policy applications.

The American College of Cardiology-National Cardiovascular Data Registry™ (ACC-NCDR™): Building a National Clinical Data Repository

Diagnostic cardiac catheterization and percutaneous coronary interventions (PCIs) are critical components of the diagnosis and treatment of patients with coronary artery disease. As the prevalence of heart disease increases in our aging population and increasingly aggressive invasive approaches are

A contemporary overview of percutaneous coronary interventions: The American College of Cardiology–National Cardiovascular Data Registry (ACC–NCDR)

The American College of Cardiology (ACC) established the National Cardiovascular Data Registry (ACC-NCDR) to provide a uniform and comprehensive database for analysis of cardiovascular procedures across the country. The initial focus has been the high-volume, high-profile procedures of diagnostic cardiac catheterization and percutaneous coronary intervention (PCI). Several large-scale multicenter efforts have evaluated diagnostic catheterization and PCI, but these have been limited by lack of standard definitions and relatively nonuniform data collection and reporting methods. Both clinical and procedural data, and adverse events occurring up to hospital discharge, were collected and reported according to uniform guidelines using a standard set of 143 data elements. Datasets were transmitted quarterly to a central facility for quality-control screening, storage and analysis. This report is based on PCI data collected from January 1, 1998, through September 30, 2000.A total of 139 hospitals submitted data on 146,907 PCI procedures. Of these, 32% (46,615 procedures) were excluded because data did not pass quality-control screening. The remaining 100,292 procedures (68%) were included in the analysis set. Average age was 64 +/- 12 years; 34% were women, 26% had diabetes mellitus, 29% had histories of prior myocardial infarction (MI), 32% had prior PCI and 19% had prior coronary bypass surgery. In 10% the indication for PCI was acute MI < or =6 h from onset, while in 52% it was class II to IV or unstable angina. Only 5% of procedures did not have a class I indication by ACC criteria, but this varied by hospital from a low of 0 to a high of 38%. A coronary stent was placed in 77% of procedures, but this varied by hospital from a low of 0 to a high of 97%. The frequencies of in-hospital Q-wave MI, coronary artery bypass graft surgery and death were 0.4%, 1.9% and 1.4%, respectively. Mortality varied by hospital from a low of 0 to a high of 4.2%. This report presents the first data collected and analyzed by the ACC-NCDR. It portrays a contemporary overview of coronary interventional practices and outcomes, using uniform data collection and reporting standards. These data reconfirm overall acceptable results that are consistent with other reported data, but also confirm large variations between individual institutions.

Impact of ethnicity and gender differences on angiographic coronary artery disease prevalence and in-hospital mortality in the American College of Cardiology-National Cardiovascular Data Registry.

Background— Although populations referred for coronary angiography are increasingly diverse, there is limited information on coronary artery disease (CAD) prevalence and in-hospital mortality other than for predominately white male patients. Methods and Results— We examined gender and ethnic differences in CAD prevalence and in-hospital mortality in a prospective cohort of patients referred for angiographic evaluation of stable angina (n=375 886) or acute coronary syndromes (ACS; unstable angina or myocardial infarction, n=450 329) at 388 US hospitals participating in the American College of Cardiology–National Cardiovascular Data Registry, an angiographic registry. Univariable and multivariable (with covariates that included risk factors, symptoms, and comorbidities) logistic regression models were used to estimate significant CAD, defined as ≥70% stenosis, and in-hospital mortality. Within stable angina and ACS cohorts, 7% of patients were black, 2% were Hispanic, 0.3% were Native American, 1% were Asian, and 90% were white, respectively. In stable angina, the risk-adjusted OR for significant CAD was 0.34 for women compared with men (P<0.0001), with black women having the lowest risk-adjusted odds (P<0.0001) compared with other females. Among ACS patients, the risk-adjusted OR of significant CAD was 0.47 for women compared with men (P<0.0001); similarly, black women had the lowest risk-adjusted odds (P<0.0001) compared with other females. Higher in-hospital mortality was reported for white women presenting with stable angina (P<0.00001). White women had a 1.34-fold (95% CI 1.21 to 1.48) higher risk-adjusted odds ratio for mortality than white men with stable angina (P<0.0001), with higher rates noted for white women who were older or had significant CAD (both P<0.0001). Lower utilization of elective coronary revascularization, aspirin, and glycoprotein IIb/IIIa inhibitors (all P<0.0001) may have contributed to higher in-hospital mortality for white women. In ACS, higher in-hospital mortality was reported for Hispanic (P=0.015) and white (P<0.0001) women; however, neither white (P=0.51) or Hispanic (P=0.13) women had higher in-hospital risk-adjusted mortality. Conclusions— The likelihood for significant CAD at coronary angiography and for in-hospital mortality varied significantly by ethnicity and gender. Future clinical practice guidelines should be tailored to gender subsets of the population, in particular for black women, to improve the efficient use of angiographic laboratories and to target at-risk populations of women and men.

Lesion morphology and coronary angioplasty: Current experience and analysis

From July 1, 1990 to February 28, 1991, 533 consecutive patients with 764 target vessels and 1,000 lesions underwent coronary angioplasty. Procedural success was achieved in 92.3%, untoward (major cardiac) events occurred in 3% (0.8% myocardial infarction, 1.3% emergency coronary bypass grafting and 0.9% both; there were no deaths). An unsuccessful uncomplicated outcome occurred in 4.7%. Lesion analysis using a modified American College of Cardiology/American Heart Association classification system showed that 8% were type A, 47.5% were type B and 44.5% were type C (36% of type B and 11% of type C were occlusions). Angioplasty success was achieved in 99% of type A, 92% of type B and 90% of type C lesions (A vs. B, p less than 0.05; B vs. C, p = NS; A vs. C, p less than 0.01). Untoward events occurred in 1.2% of type A, 1.9% of type B and 2% of type C lesions (p = NS). An unsuccessful uncomplicated outcome occurred in 0% of type A, 6% of type B and 7% of type C lesions (A vs. B, p less than 0.05; B vs. C, p = NS; A vs. C, p less than 0.05). Among the unsuccessful uncomplicated outcome group, occlusion occurred in 49%: 38% of type B and 59% of type C lesions. With B1 and B2 subtypes, success was obtained in 95% and 89.5% and untoward events occurred in 1.5% and 2.3% and an unsuccessful uncomplicated outcome in 3.7% and 8%, respectively. C1 and C2 subtyping showed success in 91% and 86%, untoward events in 1.3% and 6% and an unsuccessful uncomplicated outcome in 7.5% and 8.5%, respectively. Among the 764 vessels, success was obtained in 89.5% and untoward events occurred in 2.5% and an unsuccessful uncomplicated outcome in 8%. Assessment of lesion-vessel combinations showed a less favorable outcome with type C lesions and combinations of A-B, B-C and multiple (more than three lesions) type B and C vessels. Statistical analysis of morphologic factors associated with angioplasty success included absence of (old) occlusion (p less than 0.0001) and unprotected bifurcation lesion (p less than 0.001), decreasing lesion length (p less than 0.003) and no thrombus (p less than 0.03). The only significant factor associated with untoward events was the presence of thrombus (p less than 0.003). Predictors of an unsuccessful uncomplicated outcome included old occlusion (p less than 0.0001) and increasing lesion length (greater than 20 mm) (p less than 0.001), unprotected bifurcation lesion (p less than 0.05) and thrombus (p less than 0.03).

Development of a risk adjustment mortality model using the American College of Cardiology–National Cardiovascular Data Registry (ACC–NCDR) experience: 1998–2000

OBJECTIVES We sought to develop and evaluate a risk adjustment model for in-hospital mortality following percutaneous coronary intervention (PCI) procedures using data from a large, multi-center registry. BACKGROUND The 1998-2000 American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR) dataset was used to overcome limitations of prior risk-adjustment analyses. METHODS Data on 100,253 PCI procedures collected at the ACC-NCDR between January 1, 1998, and September 30, 2000, were analyzed. A training set/test set approach was used. Separate models were developed for presentation with and without acute myocardial infarction (MI) within 24 h. RESULTS Factors associated with increased risk of PCI mortality (with odds ratios in parentheses) included cardiogenic shock (8.49), increasing age (2.61 to 11.25), salvage (13.38) urgent (1.78) or emergent PCI (5.75), pre-procedure intra-aortic balloon pump insertion (1.68), decreasing left ventricular ejection fraction (0.87 to 3.93), presentation with acute MI (1.31), diabetes (1.41), renal failure (3.04), chronic lung disease (1.33); treatment approaches including thrombolytic therapy (1.39) and non-stent devices (1.64); and lesion characteristics including left main (2.04), proximal left anterior descending disease (1.97) and Society for Cardiac Angiography and Interventions lesion classification (1.64 to 2.11). Overall, excellent discrimination was achieved (C-index = 0.89) and application of the model to high-risk patient groups demonstrated C-indexes exceeding 0.80. Patient factors were more predictive in the MI model, while lesion and procedural factors were more predictive in the analysis of non-MI patients. CONCLUSIONS A risk adjustment model for in-hospital mortality after PCI was successfully developed using a contemporary multi-center registry. This model is an important tool for valid comparison of in-hospital mortality after PCI.

In-hospital cardiac mortality after acute closure after coronary angioplasty: Analysis of risk factors from 8,207 procedures

Cardiac death consequent to acute vessel closure after coronary angioplasty occurred in 13 of 294 closures from 8,207 consecutive procedures performed at two centers since 1981 (0.16% cardiac mortality rate). To determine the predictors of cardiac death after acute coronary closure, 50 clinical, angiographic and procedural variables were analyzed by an observer unaware of the clinical outcome for each of the 13 patients who died and also 100 patients randomly chosen, in whom vessel closure after angioplasty did not result in death during hospitalization. Univariate analysis found female gender (p less than 0.0001), collateral channels from the vessel dilated (p less than 0.0001), use of balloon counterpulsation (p less than 0.0002), pre- and postprocedural hypotension (p = 0.0003 and p = 0.003, respectively), jeopardy score greater than or equal to 2.5 (p = 0.003), left ventricular hypertrophy (p = 0.013), hypertension (p = 0.02), diabetes (p = 0.02) and multivessel disease (p = 0.03) to be predictive of death. Multivariate analysis found collateral vessels, female gender and multivessel disease to be independent predictors of death. Thus, cardiac death after elective coronary angioplasty is very rare in experienced centers and occurs most often in women with a large amount of potentially ischemic myocardium. Hypotension often precedes the fatal closure event. Close attention to the amount of potentially ischemic myocardium and to the fluid volume status of these patients would seem to be especially warranted.

A Call to ACTION (Acute Coronary Treatment and Intervention Outcomes Network) A National Effort to Promote Timely Clinical Feedback and Support Continuous Quality Improvement for Acute Myocardial Infarction

Background—There is a recognized need for a national unified registry to track presenting features, care, and outcomes for patients with acute myocardial infarction. To address this need, the American Heart Association’s Get With the Guidelines–Coronary Artery Disease program joined the Acute Coronary Treatment and Intervention Outcomes Network (ACTION) Registry to create the National Cardiovascular Data Registry ACTION–Get With the Guidelines (AR-G) in June of 2008. This article outlines the objectives, operational structure, patient population, data elements, data collection methodology, and reporting components of this landmark registry. Methods and Results—The AR-G was launched in January of 2007. The registry is led by a team of volunteers from the American Heart Association and the American College of Cardiology, and its data coordinating center resides at the Duke Clinical Research Institute. As of December 2008, 344 US hospitals already contributed detailed clinical information on 103 890 myocardial infarction patients (inclusive of 39% ST-segment myocardial infarction and 61% non–ST-segment myocardial infarction patients). Overall data quality has been excellent, with <5% clinical fields missing. Site quality improvement efforts are supported via detailed quarterly feedback reports, routine web educational programs, and sharing of “best practice” clinical support tools. Conclusions—The AR-G represents a unified, national, acute myocardial infarction registry and supports a robust quality improvement effort designed to encourage evidence-based acute myocardial infarction care and, ultimately, improve patient outcomes.

Percutaneous transluminal angioplasty of stenotic coronary artery bypass grafts: 5 years' experience.

In a 60 month period (January 1981 to December 1985), 82 patients (79% male with a mean age of 60 years) had 83 saphenous vein grafts and 5 internal mammary artery grafts with a total of 101 stenotic sites treated with percutaneous transluminal coronary angioplasty. The mean time between bypass surgery and angioplasty was 51.2 months. The procedure was technically successful in 85% of patients, 86% of grafts and 85% of the sites attempted. In these cases, the mean diameter stenosis was reduced from 77 +/- 14 to 27 +/- 20% (p less than 0.001), the mean pressure gradient from 49 +/- 16 to 7 +/- 6 mm Hg (p less than 0.001). Emergency coronary artery bypass graft surgery was necessary in one patient (1.2%) whereas myocardial infarction occurred in three patients (3.6%). There were no hospital deaths. Clinical follow-up was obtained in all 82 patients. Before angioplasty, 23% were in Canadian Cardiovascular Society functional class II, 60% in class III and 17% in class IV. With a mean clinical follow-up period of 21.4 +/- 2.3 months, 71% are in class I, 17% in class II and 12% in class III. There were two deaths, 3 months or more after angioplasty, one probably due to graft closure. So far, angiographic follow-up (at 7.9 +/- 2.1 months) has been available in 26 patients. Ten patients (with 10 grafts) exhibited graft restenosis; six of them have had second successful repeat angioplasty. Among the many variables analyzed, statistically significant predictors of success were a higher measured balloon/graft ratio (p less than 0.001), smaller diameter graft (p less than 0.001), and shorter lesion length (p less than 0.01). The only predictor of complication was diffuseness of disease in the graft (p less than 0.05). The statistically significant predictors of recurrence were the residual stenosis after the initial angioplasty (p less than 0.01) and the measured balloon/graft ratio (p less than 0.01). Angioplasty of coronary artery grafts appears to be a feasible and efficacious procedure with a low complication rate. The technique is a satisfactory alternative to repeat surgery in selected patients.