The National Cardiovascular Data Registry (NCDR) of the American College of Cardiology Foundation (ACCF) was developed to assist healthcare providers and institutions in documenting their processes and outcomes of care in the cardiac catheterization laboratory. As a resource, the NCDR is positioned to help medical professionals and participating hospitals identify and close gaps in the quality of care; reduce wasteful and inefficient care variations; and implement effective, continuous quality improvement processes. As we move into the era of transparency and public reporting, the value of the NCDR is increasing, not only for benchmarking outcomes, but also as a potent repository of clinical data to answer research questions.

A full description of the historical development of the NCDR is presented elsewhere ((1),2). Today, 1,488 facilities in the United States are enrolled in the CathPCI Registry, which captures an estimated 85% of the percutaneous coronary interventions (PCI) performed in the United States (Figure 66_gr1). The Society for Cardiovascular Angiography and Interventions collaborates with the ACCF on the registry effort.

Participation in the NCDR CathPCI Registry is voluntary. Most participating facilities (68%) submit data on diagnostic catheterization and PCI procedures, 29% submit data only on PCI procedures, and 3% provide information only on diagnostic procedures. Because interventional practices are driven by technologies that change quickly, there have been several registry modifications leading to the current version 4.4 that began receiving data on April 1, 2011. This version expanded data collection on pre-catheterization imaging procedures, used a new bleeding definition, and provided the first report of test metrics for assessment of the appropriate use criteria for coronary revascularization. The current version has 253 data fields, with definitions and specifications available online (3). Data are collected up to the time of hospital discharge, which is a potential limitation (4).

The NCDR Data Quality Program was developed to ensure that data submitted are complete, consistent, and accurate and thus usable to improve the quality of clinical practice. Participant submissions are reviewed for completeness and are not accepted if data completeness criteria are unmet. Each year, 25 sites are selected randomly for a comprehensive on-site data audit. The structure of the Data Quality Program and audit results recently were reported (5). Several states conduct more extensive audits of data, because they are used for statewide reporting programs.

Participants in the registry receive quarterly reports reflecting their aggregate data and a rolling summary of the previous 4 quarters. Results from facilities with similar procedure volumes and from the entire registry are provided for comparison with a recent online tool developed to allow facilities to perform a detailed analysis of their own data. An executive summary of key metrics is provided in a box-and-whisker plot format (Figure 66_gr2). The NCDR provides an in-hospital risk-adjusted mortality model that is endorsed by the National Quality Forum ((6),7). Bleeding and acute kidney injury risk models also have been developed (8).

These data provide a contemporary snapshot of diagnostic cardiac catheterization and PCI as performed in the United States, and thus provide an important perspective on many aspects of invasive cardiac procedures, including their current use and outcomes (9). Summary reports from the Implantable Cardioverter Defibrillator Registry have been published (10), and it is the intent of the NCDR to publish aggregate data from all its registries in the future.

The following sections provide an overview of invasive cardiology as cataloged by the NCDR. The tabular data and figures represent summary data for 6 consecutive calendar quarters using version 4 beginning January 1, 2010, and ending June 30, 2011. Data are presented in 2 groups representing patients undergoing only diagnostic cardiac catheterization (n = 1,110,150) and patients undergoing PCI (n = 941,248) during their episode of care.

Among the facilities included in this report, 49% performed 400 or fewer PCI procedures annually and 13% performed more than 1,000 PCI procedures annually (Figure 66_gr3). Three hundred thirty-nine facilities (26%) performed 200 or fewer PCI procedures annually, and these facilities accounted for approximately 4% of the total PCI procedures (Figure 66_gr4). PCI without on-site cardiac surgery was performed at 32.6% of facilities, representing 12.4% of all PCI procedures performed. Among facilities performing PCI without on-site surgery, 89% had a case volume of fewer than 400 PCI procedures annually. Although data showing a relationship between case volume and outcomes are mixed and uncertain, the 2011 PCI guidelines recommend that low-volume operators (fewer than 75 cases annually) not perform PCI procedures at low-volume facilities (fewer than 400 procedures annually) and that facilities performing fewer than 200 PCI procedures annually, unless geographically isolated, carefully consider whether to continue to offer this service (11).

Demographic data for patients undergoing only diagnostic procedures and those undergoing PCI are shown in (Table 1). Approximately two-thirds of those undergoing PCI were male, whereas 56% of those undergoing diagnostic study were male (Figure 66_gr5). Median age and the age distribution were similar for the 2 groups, with approximately half of the patients being 65 years of age or older and approximately 10% of the patients being 80 years of age or older (Figure 66_gr5). Coronary intervention was performed during the same laboratory session as the diagnostic catheterization (so called ad hoc PCI) in 85.7% of the records.

Approximately 80% of the patients were overweight (body mass index ≥25 kg/m²), approximately 45% were obese, and approximately 1% were considered thin (body mass index ≤18.5 kg/m²) ((Table 2),Figure 66_gr6). The occurrence of other clinical characteristics and risk factors also is shown. Among diabetic patients undergoing PCI, 36% were treated with insulin, 52% were treated with oral agents, 6% were treated with diet alone, and 5% were receiving no treatment.

Among patients undergoing PCI, approximately 70% had some type of acute coronary syndrome at presentation (unstable angina, non–ST-segment elevation myocardial infarction, ST-segment elevation myocardial infarction [STEMI]), 17.6% had stable angina, and 12% had either atypical symptoms or no angina ((Table 3),Figure 66_gr7). In comparison, of those undergoing only diagnostic study, 43.5% had an acute coronary syndrome at presentation—mostly unstable angina, 21.4% had stable angina, and 35.2% had either atypical or no symptoms. Heart failure within the previous 2 weeks, cardiogenic shock within the previous 24 h, and cardiac arrest were uncommon at the time of presentation in both groups. Pre-operative diagnostic catheterization before noncardiac surgery was uncommon (4.9%), as was pre-operative PCI (2.0%). Medication use, especially in patients undergoing PCI, has been examined recently within the NCDR database (12). Nearly 70% of patients undergoing PCI were prescribed antianginal medications within 2 weeks of their procedure; 44% had 1 drug prescribed, whereas 24% had 2 or more drugs prescribed. Among patients with at least 1 antianginal medication prescribed, beta-blockers were used most frequently (87%), followed by long-acting nitrates (26.1%) and calcium-channel blockers (22.5%).

Among patients undergoing diagnostic catheterization, 45.5% underwent some type of stress test before their procedure, but it is important to note that this includes patients undergoing study for all indications, not just coronary artery disease (CAD) (Table 4). Among patients undergoing PCI, 33.6% had undergone some type of stress study before PCI, but not all patients undergoing PCI would be appropriate candidates for a stress study. If patients who would likely not undergo stress testing are excluded (immediate PCI for STEMI, PCI for STEMI in unstable patients more than 12 h from symptom onset, rescue PCI for failed fibrinolytics, and PCI for high-risk non–ST-segment elevation myocardial infarction or unstable angina), 52.0% of patients underwent some type of stress test before PCI. As a PCI quality metric, the proportion of elective PCIs with either an abnormal stress study suggesting ischemia or a fractional flow reserve measurement 0.8 or less before PCI was assessed. The 50th percentile for this metric among all facilities was 58.7%; facilities in the top 10% for this metric obtained such testing in 76.9% of elective PCIs.

The dominant form of stress testing used was a myocardial perfusion study (Figure 66_gr8). Across all types of stress studies in patients undergoing PCI, 9% to 12% demonstrated negative results, 3% to 6% demonstrated indeterminate results, and 81% to 88% demonstrated abnormal results. An assessment of ischemic risk from the stress study was provided in approximately 60% of the patients and indicated intermediate or high risk in 79% to 87% of PCI patients and in 66% to 76% of those undergoing diagnostic cardiac catheterization. Less than 1% of patients in the database underwent stress testing using magnetic resonance imaging. Overall, coronary calcium scores and coronary computed tomography angiography were performed in few patients before the procedure.

For both diagnostic procedures and PCI, femoral access remains the most frequently used technique (Table 5). Mean and median fluoroscopy times for the entire cohort undergoing diagnostic catheterization are shown. These times are affected by the need to image bypass grafts if present and other diagnostic imaging such as left ventriculography. Because most PCI procedures were performed ad hoc, fluoroscopy time further depended on the number of vessels or lesions treated. Therefore, times were stratified further for single-vessel or single-lesion procedures versus multivessel procedures. As total radiation exposure receives greater attention, the values shown for fluoroscopy times are useful benchmarks for facilities to identify operators who may use excessive radiation consistently for procedures. Mean and median amounts of radiographic contrast, stratified in a similar manner, also are provided in (Table 5).

Manual compression was the most frequent method used to obtain hemostasis for both diagnostic studies and PCI (Figure 66_gr9). Sealant-type devices are the next most frequently used, whereas staple closure devices represented less than 0.1% of the devices used.

Anticoagulant and antiplatelet use is shown in (Figure 66_gr10). Overall, aspirin was given within the 24 h before and during PCI in 87.8% of patients and was contraindicated in 0.7% of patients. By hospital discharge, nearly all patients without a contraindication were receiving aspirin; the 50th percentile of aspirin administration at discharge was 97.9% among all facilities, and in the 90th percentile (top 10% of performers), the aspirin administration rate was 99.7%. Clopidogrel was the most frequently used thienopyridine (76%), with prasugrel used in 11.2% of patients and ticlopidine used in only 0.25% of patients. Ticagrelor was not available commercially during this survey period. By hospital discharge, nearly all patients were receiving a thienopyridine; the 50th percentile of thienopyridine use among all facilities was 98.9% and the 90th percentile was 100%. Fondaparinux was used rarely (1.1%) in patients before or during PCI, with unfractionated heparin or bivalirudin used approximately equally (51% and 56%, respectively). Glycoprotein IIb/IIIa inhibitors were used overall in 28.7% of PCIs and slightly more frequently among patients with an acute coronary syndrome (34.0%). By hospital discharge, nearly all patients without a contraindication were receiving a statin medication; the 50th percentile among facilities for the administration of a statin at discharge was 90.5% and the 90th percentile was 96.5%.

Considering patients undergoing only diagnostic procedures, 49.8% had either no CAD or nonobstructive CAD, whereas only 0.2% in the PCI cohort were classified as having all stenoses less than 50% in severity (Table 6). This seems to suggest that many diagnostic procedures were performed on patients without significant CAD. However, diagnostic studies are performed for reasons besides CAD. A more informative quality metric was developed for elective diagnostic procedures excluding patients: 1) with prior coronary artery bypass graft (CABG); 2) undergoing cardiac transplantation evaluation; 3) undergoing pre-operative evaluation for noncardiac surgery; and 4) those with a treatment recommendation other than PCI or CABG. An example of the latter would be an older patient with isolated valvular disease in whom coronary angiography is performed before valve surgery. In this restricted cohort, procedures with the finding of all coronary stenosis of less than 50% occurred at a median of 44.5% among facilities; at the 90th percentile, the value for all coronary stenosis of less than 50% was 32.6%. Furthermore, because a coronary stenosis of less than 50% can be associated with unstable coronary syndromes and roughly 10% of patients with STEMI are found to have normal coronary arteries, a finding of less than 50% stenosis in a large number of patients does not automatically indicate an overuse of diagnostic angiography (13). However, as previously reported, there is significant interhospital variation in the rate of finding obstructive CAD among patients undergoing elective, diagnostic coronary angiography (14). Left main disease (≥50%) was found in 8.2% of patients undergoing diagnostic study and in 6.4% of patient undergoing PCI, usually in conjunction with additional CAD.

Among patients undergoing only diagnostic study, the treatment recommendations were medical therapy in 69.2%, CABG in 13.0%, no subsequent therapy in 9.2%, and other cardiac therapy without CABG or PCI in 6.3%. In 2.1%, PCI without planned CABG was recommended, but was performed as a separate procedure. The indications for PCI are also shown in (Table 6) and (Figure 66_gr11).

Characteristics of the entire cohort of patients undergoing PCI are shown in (Table 7) and (Figure 66_gr12). In 6.0% of the total lesions, PCI of a bypass graft was performed, mostly in vein grafts, with 58.4% occurring in the body of the vein graft. Although PCI of arterial grafts was uncommon, when performed, it was most frequently at the distal anastomosis or in the graft body. Data on devices used were collected, and their use on a per-procedure basis was estimated. All of the adjunctive devices were used infrequently. At least 1 drug-eluting stent (DES) was used in 69.8% of PCI patients, a bare-metal stent (BMS) with no DES was used in 21.5% of PCI patients, and balloon angioplasty without stent use was used in 8.7% of patients. On average, 1.4 stents were placed per procedure performed. When DES were used, 61.6% of the patients received just 1 DES, 26.2% had 2 DES used, 8.6% had 3 DES used, and 3.6% had 4 or more DES used. When BMS were used, 70.0% of the patients received just 1 BMS, 21.9% had 2 BMS used, 6.0% had 3 BMS used, and 3.6% had 4 or more BMS used. The longest lesion length treated during PCI was more than 25 mm in 23% of patients, 10 mm or more but less than 15 mm in 24.5%, and less than 10 mm in 7.7% of patients. Bifurcation lesions were treated in 13% of patients.

Approximately 13% of all stenoses treated by PCI were graded between 40% and 70% in severity. In this subgroup, 25% were evaluated further by either intravascular ultrasound (18%) or fractional flow reserve measurements (7%). In patients with stenoses graded between 40% and 70% in severity treated by PCI, only 8.3% had either no angina or normal stress test results, and approximately 23% of these stenoses were further evaluated by intravascular ultrasound or fractional flow reserve measurements.

Cardiogenic shock was present in the preceding 24 h in 1.9% of patients undergoing PCI during admission (Table 3) and developed during or after PCI in 0.47% of patients (Table 8). Some type of mechanical support device was used in 2.9% of all PCIs performed. This was dominated by the intra-aortic balloon pump that was used alone in 84.4% of the cases with mechanical support or with another support device in 4.7%. However, the timing of support device insertion was different between intra-aortic balloon pumps and other support devices. When intra-aortic balloon pumps were used, they were in place before the procedure in 8.1%, were inserted during the procedure and before PCI in 29.3%, and inserted after the start of the PCI in 62.6%. By contrast, when other forms of mechanical support were used, they were in place at the start of the procedure in 36.3%, were inserted during the procedure and before PCI in 46.2%, and were inserted after the start of the PCI in 17.4%.

Any adverse event occurred in 4.53% of patients undergoing PCI and in 1.35% of patients undergoing diagnostic cardiac catheterization (Table 8). Any bleeding within 72 h occurred in 1.40% of PCI patients without STEMI and in 0.49% of patients undergoing diagnostic cardiac catheterization without STEMI. (Figure 66_gr13) shows the type of bleeding event that occurred in patients undergoing diagnostic catheterization and PCI with or without STEMI.

(Table 9) shows the quality metrics and complications in STEMI patients. The median time (50th percentile) from hospital arrival to PCI for nontransfer STEMI patients (door-to-balloon time) was 64.5 min—a marked reduction in door-to-balloon times over a few years that reflect the success of focused process improvement initiatives (15). Nonsystem delays were identified in STEMI patients with a door-to-balloon time of more than 90 min. Reasons listed for nonsystem delay included difficult vascular access (7.4%), cardiac arrest or need for intubation before PCI (36.2%), delays in providing consent for PCI (4.4%), difficulty crossing the culprit lesion during PCI (17.4%), and other reasons in (34.6%).

The 50th percentile for hospital risk-adjusted mortality rate among STEMI patients was 5.2%, and facilities in the top 25th percentile for this metric had a risk-adjusted mortality rate of 3.3%. The top 10th percentile for risk-adjusted STEMI mortality is not reported because it likely was skewed by the number of low-volume facilities reporting no STEMI mortalities. Among STEMI patients undergoing PCI, any adverse event occurred in 12.4%, with specific complications shown in (Table 9) and bleeding complications in (Figure 66_gr13).

Procedure success typically is defined as angiographic success without associated in-hospital major clinical complications (e.g., death, myocardial infarction, stroke, emergency CABG) (11). Because of the known variability in the visual assessment of stenosis severity and the high likelihood of a good visual result after stent deployment, angiographic success no longer is reported from the CathPCI Registry. However, to provide some perspective for this report, PCI success was defined as completion of the procedure without death, CABG related to PCI failure, PCI failure without clinical deterioration, stroke, pericardial tamponade, or need for dialysis and is shown in (Figure 66_gr14). Myocardial infarction was not included in this definition because cardiac enzymes were not collected consistently in patients after PCI.

For diagnostic procedures, 65.5% were classified as elective, 31.4% were classified as urgent, 3.0% were classified as emergent, and 0.1% were classified as salvage. For PCI procedures, 44.8% were classified as elective, 37.5% were classified as urgent, 17.3% were classified as emergent, and 0.3% were classified as salvage. Unadjusted mortality for PCI patients in these categories is shown in (Figure 66_gr15).

The value of the CathPCI Registry will be demonstrated as it is used to understand further the practice of invasive cardiology and to drive a higher level of quality into individual physician practice. The ACCF and its registry partners are committed to expanding the NCDR to its full potential as the delivery of health care continues to evolve.

Since its inception, the CathPCI Registry has been the substrate for more than 70 publications in the peer-reviewed medical literature and for more than 200 abstracts presented at national meetings. These and additional publications continue to provide key insights into the important clinical issues in the rapidly changing field of invasive cardiology.

Physicians who have a time-limited board certification from the American Board of Internal Medicine must complete a Maintenance of Certification process to renew their certification. CathPCI Registry data can be used to complete American Board of Internal Medicine's Self-Directed Practice Improvement Module and meet the American Board of Internal Medicine's Self-Evaluation of Practice Performance requirement (16). The goal is to use actual data from an individual's practice setting to drive quality improvement efforts. Moving forward, there are many additional areas where the organizations share common goals for collaboration, including efforts to enhance life-long learning.

Public reporting of outcomes is increasing in an attempt to encourage both physicians and hospitals to become engaged in quality efforts, to improve areas where problems exist, and to provide patients with information about comparative performance. Public reporting of cardiac surgical outcomes is not new and exists in several states, and the Society of Thoracic Surgeons (STS) recently instituted a voluntary public reporting effort with Consumer's Union ((17),18). For such reporting, there is an important distinction between administrative (claims) data and clinical data sources. Disparities in the results between these 2 datasets have been demonstrated, with report cards using only administrative data often being different when compared with those derived from audited and validated clinical data (19). Concern exists that such programs may lead to unintended consequences that could offset their benefits (20). The NCDR is developing a plan for voluntary public reporting of selected NCDR data. Public reporting efforts of the STS have been received favorably, and the NCDR will follow the principles set forth by the ACCF ((21),22).

The ASCERT (American College of Cardiology Foundation–The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization sTrategies) study is a unique collaboration between the ACCF and the STS (23). This study compared catheter-based and surgery-based revascularization procedures for stable CAD using existing databases from the ACCF and STS, as well as the Centers for Medicare and Medicare Services 100% denominator file data. Other efforts to merge NCDR data with longitudinal administrative datasets provides an efficient and low-cost method to perform longitudinal outcome assessments ((24),25).

Beginning in February 2011, Sheikh Khalifa Medical City in Abu Dhabi, United Arab Emirates, began data collection for the ACTION Registry-GWTG and CathPCI Registry. Discussions are underway to include NCDR participation for all hospitals in this system and with several other international facilities. Further international expansion of the NCDR provides several unique opportunities for comparisons among regions and different systems of care.