Coronary Catheterization and Percutaneous Coronary Intervention in China: 10-Year Results From the China PEACE-Retrospective CathPCI Study

Importance  The use of coronary catheterization and percutaneous coronary intervention (PCI) is increasing in China, but, to date, there are no nationally representative assessments of the quality of care and outcomes in patients undergoing these procedures.

Objective  To assess the quality of care and outcomes of patients undergoing coronary catheterization and PCI in China.

Design, Setting, and Participants  In a clinical observational study (China PEACE [Patient-Centered Evaluative Assessment of Cardiac Events]–Retrospective CathPCI Study), we used a 2-stage, random sampling strategy to create a nationally representative sample of 11 241 patients undergoing coronary catheterization and PCI at 55 urban Chinese hospitals in calendar years 2001, 2006, and 2011. Data analysis was performed from July 11, 2014, to November 20, 2015.

Main Outcomes and Measures  Patient characteristics, treatment patterns, quality of care, and outcomes associated with these procedures and changes over time.

Results  Of the 11 241 patients included in the study, the samples included, for 2001, 285 women (weighted percentage, 28.6%); for 2006, 826 women (weighted percentage, 32.2%), and for 2011, 2588 women (weighted percentage, 35.7%). Mean (SD) ages were 58 (8), 60 (11), and 61 (11) years, respectively. Between 2001 and 2011, estimated national rates of hospitalizations for coronary catheterization increased from 26 570 to 452 784 and for PCI, from 9678 to 208 954 (17-fold and 21-fold), respectively. More than half of stable patients undergoing coronary catheterization had nonobstructive coronary artery disease; this amount did not change significantly over time (2001: 60.3% [95% CI, 56.1%-64.5%]; 2011: 57.5% [95% CI, 55.8%-59.3%], P = .05 for trend). The proportion of PCI procedures performed via radial approach increased from 3.5% (95% CI, 1.7%-5.3%) in 2001 to 79.0% (95% CI, 77.7%-80.3%) in 2011 (P < . 001 for trend). The use of drug-eluting stents (DESs) increased from 18.0% (95% CI, 14.2%-21.7%) in 2001 to 97.3% (95% CI, 96.9%-97.7%) in 2011 (P < .001 for trend) largely owing to increased use of domestic DESs. The median length of stay decreased from 14 days (interquartile range [IQR], 9-20) in 2001 to 10 days (IQR, 7-14) in 2011 (P < .001 for trend). In-hospital mortality did not change significantly, but both adjusted risk of any bleeding (odds ratio [OR], 0.53 [95% CI, 0.36-0.79], P < .001 for trend) and access bleeding (OR, 0.23 [95% CI, 0.12-0.43], P < .001) were decreased between 2001 and 2011. The medical records lacked documentation needed to calculate commonly used process metrics including door to balloon times for primary PCI and the prescription of evidence-based medications at discharge.

Conclusions and Relevance  Although the use of catheterization and PCI in China has increased dramatically, we identified critical quality and documentation gaps that represent opportunities to improve care. Our findings can serve as a foundation to guide future quality improvement initiatives in China.

In China, the dramatic increase in the burden of ischemic heart disease has been accompanied by expanded use of coronary catheterization and percutaneous coronary intervention (PCI).^1-4 This growth has occurred during a period of dynamic change within the Chinese health care system, characterized by substantial investments in health care infrastructure and broader availability of health insurance coverage. Today, China faces a challenge in ensuring that invasive cardiovascular procedures are performed appropriately, safely, and efficiently. However, the rapid growth in procedural volume has not been accompanied by efforts to systematically monitor the quality of care and outcomes of patients undergoing these procedures, due in part to limited resources to support quality improvement activities.⁵ The absence of a national assessment of the practice of interventional cardiology remains an important barrier to the identification of gaps in care and the implementation of quality improvement efforts.

To provide a comprehensive overview of coronary catheterization and PCI in China over the past decade, we conducted the China PEACE (Patient-Centered Evaluative Assessment of Cardiac Events)–Retrospective Study of Coronary Catheterization and Percutaneous Coronary Intervention (China PEACE-Retrospective CathPCI Study). The study identified a representative sample of 55 urban hospitals performing PCI and abstracted the medical records of 11 241 patients who underwent coronary angiography or PCI during calendar years 2001, 2006, and 2011.⁶ We assessed patient characteristics, treatment patterns, quality of care, and in-hospital outcomes of patients undergoing coronary catheterization and PCI in China and their change over time.

Box Section Ref ID

The design of the China PEACE-Retrospective CathPCI Study (NCT01624896) has been published previously.^6,7 In brief, we used a 2-stage, random sampling design to create a representative sample of patients undergoing coronary catheterization within urban regions, as catheterization capability is restricted almost exclusively to these regions, in 2001, 2006, and 2011. In the first stage, we divided urban areas into 2 study strata: eastern-urban and central/western-urban. We used a simple procedure to randomly sample among the highest-level hospitals in each stratum. We selected representative hospitals from 2011 to reflect current practices and traced this cohort of hospitals back to 2006 and 2001 to identify hospitals in these time periods. In the second stage, we identified all eligible cases within each sampled hospital using a systematic random sampling procedure. We doubled cluster sizes for 2011 to improve the precision of estimates on hospital-level treatment patterns and outcomes for this year. We collected data through central abstraction of medical records using standard data definitions. To ensure data quality, we monitored data abstraction by random auditing of 5% of the medical records, with accuracy exceeding 98%.⁶

Both the central ethics committee at the China National Centre of Cardiovascular Disease and the Human Investigation Committee of the Yale University School of Medicine approved the China PEACE-Retrospective CathPCI Study. The need for informed consent was waived. Fifty collaborating hospitals accepted the central ethics committee approval, and 5 hospitals received approval from their local ethics committees.

Patients undergoing coronary catheterization or PCI at participating hospitals for any indication were included in the study sample. For the analysis of in-hospital outcomes and the proportion of PCI procedures with serum creatinine levels and cardiac biomarkers assessed post-PCI, patients who were transferred out were excluded.

We investigated the discharge diagnoses of patients undergoing coronary angiography and PCI. Patients with a discharge diagnosis consistent with coronary artery disease (CAD) but not acute coronary syndromes were considered to have stable CAD. If the local diagnosis was not definitive, cardiologists at the coordinating center reviewed the medical record to determine a discharge diagnosis.

We abstracted patient demographics, clinical characteristics, and treatment patterns with regard to indications for coronary catheterization and PCI; PCI-related characteristics and adjunctive therapies; and medications used during hospitalization and prescribed at discharge. We determined whether the medical record captured key variables needed to assess quality of PCI care including assessment of serum creatinine levels, cardiac biomarkers, contrast volume, procedural success, and the timeliness of primary PCI.⁸ In addition, we assessed whether medications prescribed at discharge were documented in the medical record, and the proportion of patients for whom discharge medication information on aspirin, a thienopyridine, and/or a statin was documented. Finally, among the patients undergoing PCI, we assessed in-hospital outcomes by collecting data on death, treatment withdrawal, a major adverse cardiac event (death, treatment withdrawal,^9,10 stroke, or repeated target vessel revascularization), bleeding events, and length of stay. Bleeding events were classified as any bleeding, major bleeding, access bleeding, and bleeding requiring blood transfusion. The relevant definitions are described in eMethods in the Supplement.

We used percentages with 95% CIs to describe categorical variables and medians with interquartile ranges (IQRs) to describe continuous variables. To estimate nationally representative rates in each study year, we calculated the sampling weights proportional to the inverse sampling fraction of patients within each stratum, which equals the product of the sampling fraction of patients within each hospital and the sampling fraction of hospitals within each stratum, then standardized them within each year to the total sampling number of the year so that the comparison would not be affected by differences in sample size (eMethods in the Supplement). We applied these standardized weights for all analyses. We examined changes in geographic and clinical characteristics, treatment patterns, unadjusted rate and adjusted odds ratio (OR) of outcomes, and quality metrics across different study years using the Cochran-Armitage trend test for the trend of binary variables and the Mann-Kendall trend test for trends of continuous variables. All trend tests were based on 3 time points (2001, 2006, and 2011).

To compare the adjusted risk of in-hospital death, death or treatment withdrawal, composite end points, and bleeding events, we used time indicators for 2006 and 2011 as key explanatory variables with 2001 as the reference group. Given the relatively low rates of outcomes, we selected the variables that were both clinically and statistically significantly associated with the risk of adverse outcomes (eMethods and eTables 1-7 in the Supplement).^11,12 These variables included cardiogenic shock, ST-segment elevation myocardial infarction (STEMI) vs non-STEMI, estimated glomerular filtration rate, sex, and age. To account for clustering of patients within hospitals, we established multilevel logistic regression models with use of generalized estimating equations. We reported ORs and 95% CIs from the multilevel logistic regression related to the year indicators. The linear trend over time in the models was tested.

All comparisons were 2-sided, with statistical significance defined as P < .05. Statistical analyses were performed using SAS, version 9.2 (SAS Institute Inc) and R, version 3.0.2 (https://www.r-project.org/).

From a total of 833 urban hospitals, we sampled 70 hospitals and invited them to participate in the study. We excluded 15 hospitals because they did not provide inpatient services (n = 5), had no capability for coronary catheterization or PCI (n = 8), or declined participation (n = 2). Among the remaining 55 hospitals, the availability of coronary catheterization and PCI services varied over time (2001, 24 hospitals; 2006, 44 hospitals; and 2011, 54 hospitals). Examination of patient databases from the 55 hospitals yielded 58 731 eligible hospital admissions. We randomly identified a subset of 12 477 hospitalizations and acquired 11 900 medical records (95.4%). We excluded 659 ineligible hospitalizations, providing a final sample of 11 241 hospitalizations with coronary catheterization (1000 in 2001, 2755 in 2006, and 7486 in 2011) of which 5460 (48.6%) cases included a PCI (eFigure in the Supplement). After weighting these data to estimate national rates, the use of coronary catheterization and PCI increased by 17-fold and 21-fold, respectively, between 2001 and 2011 (coronary angiography: 26 570 in 2001, 133 942 in 2006, and 452 784 in 2011; PCI: 9678 in 2001, 62 308 in 2006, and 208 954 in 2011) (Figure 1).

Between 2001 and 2011, there were modest changes in the characteristics of patients undergoing coronary catheterization. Compared with 2001, higher proportions of patients in 2011 were female, aged 70 years or older, and had comorbid conditions including diabetes mellitus, hypertension, and prior PCI. However, the proportions of patients with renal dysfunction (estimated glomerular filtration rate, ≤60 mL/min/1.73 m²) and prior myocardial infarction (MI) were lower. Among all the patients undergoing coronary catheterization, the proportion of cases with STEMI decreased but that of NSTEMI increased. Compared with 2001, a lower proportion of patients in 2006 and 2011 had nonobstructive CAD and a higher proportion of patients were found to have left main CAD. However, among stable patients, the proportion of patients with nonobstructive CAD did not change significantly over time (P = .05 for trend) (Table 1).

The characteristics of patients undergoing PCI showed changes over time similar to those of the overall study population. The proportion of patients with high-risk features, including cardiogenic shock and cardiac arrest at admission, did not change significantly over time (eTable 8 in the Supplement). Although the proportion of PCIs performed in the context of STEMI decreased, the proportion of patients undergoing primary PCI did not change significantly over time. In contrast, the proportions of PCIs performed on patients with NSTEMI increased during the study period (Figure 1 and eTable 9 in the Supplement).

From 2001 to 2011, there was a significant increase in the proportion of PCI procedures through radial access. Among procedures with femoral access, vascular closure devices were used in less than 10% of cases—a proportion that did not change substantially from 2001 to 2011. The majority had a single vessel treated, and nearly a quarter of patients in 2011 underwent PCI of more than 1 vessel. The proportion of cases in which a left main lesion was treated increased slightly, and there were significant increases in the use of drug-eluting stents (DESs), particularly domestic DESs. The use of fractional flow reserve and intravascular ultrasonography was low in all time periods (Table 2). The proportions of patients who received a glycoprotein IIb/IIIa inhibitor and clopidogrel bisulfate both increased from 2001 to 2011. The use of statins during hospitalization increased from 60.1% in 2001 to 94.6% in 2011 (eTable 10 in the Supplement).

For most quality metrics, the information documented in the medical record was frequently incomplete. For example, in 2011, among patients undergoing primary PCI, only 3.0% and 0.5% of patients had the information about hospital arrival time and balloon dilation time—the key elements needed to determine their door to balloon time. Similarly, in 2011, records on 51.5% of the PCIs lacked documentation about whether or not the procedure was successful, and 36.3% of PCI cases had no documented information about discharge medications. Documentation improved for a few metrics over time including the proportion of patients with a serum creatinine level assessed before the procedure and information on contrast volume. However, documentation for most metrics, including proportion of primary PCI procedures recording hospital arrival time and balloon dilation time, as well as the proportion of procedures with cardiac biomarkers assessed after PCI, did not improve from 2001 to 2011 (Figure 2 and eTable 11 in the Supplement).

The median hospital length of stay was 14 days (IQR, 9-20) in 2001, 11 days (IQR, 8-16) in 2006, and 10 days (IQR, 7-14) in 2011 (P < .001 for trend). The unadjusted rates of most adverse outcomes did not change over the study period, including the mortality of patients undergoing primary PCI (eTable 12 in the Supplement). The rate of death or treatment withdrawal was 0.6% in 2011. However, the rates of both any bleeding and access bleeding events were lower in 2011 than 2001. Similarly, in multivariable analysis, both adjusted risk of any bleeding (OR, 0.53 [95% CI, 0.36-0.79], P < .001 for trend) and access bleeding (OR, 0.23 [95% CI, 0.12-0.43], P < .001 for trend) were decreased between 2001 and 2011, and the adjusted risks of other outcomes were similar across time periods (Figure 3).

To our knowledge, the China PEACE-Retrospective CathPCI Study is the first large, nationally representative study of hospitals in China performing coronary angiography and PCI. We found that the dramatic increase in the rate of hospitalization for coronary catheterization and PCI reflected growth in procedures performed on patients with both stable CAD and acute coronary syndrome. There have been substantial changes in clinical practice, most notably the widespread adoption of radial access and the routine use of DESs, especially domestic DESs. Most importantly, our study identified opportunities to improve the quality of care delivered to patients undergoing these procedures. A substantial proportion of stable patients undergoing diagnostic catheterization had insignificant CAD. Moreover, the medical records of many patients undergoing PCI lacked documentation of important process measures needed to assess quality of care. These findings serve as a foundation to guide future efforts on quality improvement in the use of coronary catheterization and PCI in China.

Our findings suggest that there may be an opportunity to improve the selection of patients referred for elective coronary catheterization. Among stable patients undergoing coronary angiography, more than half had no hemodynamically significant stenosis, and this proportion did not change significantly over time. This finding is not unique to China, with studies^13-15 of countries with different health care systems demonstrating similarly low yields of coronary angiography. We cannot determine whether this finding reflects limited access to appropriate noninvasive testing, patient preference, or other unmeasured factors. Regardless, there may be an opportunity to improve care by prioritizing efforts to ensure that patients undergo appropriate risk stratification before the performance of coronary angiography.^16,17

We identified several important changes in the practice of interventional cardiology in China. First, radial artery access was widely adopted during this timeframe, increasing from 3.5% to 79.0%. The emergence of radial access as the preferred vascular access strategy is supported by studies^18-20 demonstrating higher patient satisfaction, reduced length of stay, and lower risk of procedural complications with this technique. However, the use of radial access varies by country and region.²¹ In the United States, for example, only 16.1% of PCIs were performed using radial access in 2011.²² Given the established benefits of radial access, understanding the factors that facilitated the rapid adoption of this technique in China may help to promote the adoption of radial access PCI in countries that use it less frequently.²³

Second, during the study period, physicians increasingly used medicated stents such that, in 2011, virtually all (97.3%) implanted stents were DESs. The proportion of patients with PCI who received a DES varies across countries. In the United States 69.8% of patients undergoing PCI receive a DES, compared with 76.9% in Australia and 93.0% in Korea.^13,24,25 Although the optimal proportional use of DESs has not been established, their near universal use in China may indicate an opportunity to align stent selection with patient preference, underlying risk of restenosis, cost, and suitability for long-term dual antiplatelet therapy.^26,27 In addition, we found that most DESs were domestically produced. Although several small studies^28-32 have suggested that these stents perform similarly to imported DESs, conclusive evidence is lacking. The outcomes of patients who receive domestic DESs is the focus of an ongoing, multicenter retrospective study.³³

A previous study³⁴ identified significant gaps in the quality of care provided to patients with acute MI in China. Our study builds on these findings, demonstrating that the need to improve care extends to patients with both stable and unstable cardiovascular disease. We found that the medical records often lacked information needed to assess the quality of medical care. This gap may represent poor care or simply reflect poor documentation, but in the absence of this information, we cannot determine whether these procedures are appropriate, safe, effective, and timely. We believe that the development of a prospective national registry to collect information using standardized data definitions would promote quality improvement efforts by allowing hospitals to benchmark their performance. Such an effort would require a substantial investment by hospitals and health care professionals, but this would represent a key step toward the goal of creating a learning health care system.³⁵

In China, an in-hospital mortality of 0.6% following PCI is lower than that reported in contemporary North American and European studies.^13,36-39 This finding may be associated with differences in case selection wherein patients at highest risk of adverse outcomes were not undergoing PCI. In China, many patients with STEMI did not receive timely revascularization,³⁴ and in our study, the proportions of patients with cardiac arrest or cardiogenic shock were lower than those reported in the United States.¹³ Although we did not observe substantial changes in the risk of death or treatment withdrawal from 2001 to 2011, our study may have been underpowered to detect clinically important differences in patient outcomes over time. However, we observed a lower risk of any bleeding and access bleeding events over time, despite an increasing use of glycoprotein IIb/IIIa inhibitors.

The findings of this study should be interpreted in the context of several limitations. First, we abstracted clinical variables on the basis of documentation in medical records, and the completeness of that documentation may not have been consistent either across hospitals or over time. Nevertheless, the use of centralized data abstraction ensured that the review was consistent and accurately reflected what had been recorded in the medical records. Second, we were unable to collect information needed to identify elective procedures, and we had limited information about the use of adjunctive studies, such as stress testing and coronary computed tomography performed before the hospitalization. As such, we were unable to evaluate the appropriateness of diagnostic catheterization and PCI procedures.⁴⁰ Third, the diagnosis of unstable angina was based solely on discharge diagnosis in medical records. It is possible that the proportion of patients with unstable angina may represent an overdiagnosis of unstable angina. However, this proportion is similar to that observed in the United States.¹³ Finally, our study was limited to procedures performed in 2011 or earlier, and our findings may not reflect current practice patterns. Despite these limitations, the study has provided what we believe to be the most comprehensive overview of contemporary practice of interventional cardiology in China.

The use of catheterization and PCI in China has increased substantially from 2001 to 2011. However, changes in procedural volume have not been matched by the development of systems to ensure that the care delivered to these patients is evidence-based, safe, and efficient. Developing such a system is particularly important in a country with constrained resources and large variation among health care professionals. Although the Chinese Ministry of Health has initiated preliminary efforts to standardize the care of patients undergoing PCI, more work is necessary.⁴¹ A comprehensive strategy is needed, including development of a national system that prioritizes data collection, performance measurement, public reporting, and quality improvement.³⁵ Our findings can serve as a foundation to guide efforts to further improve the quality of care and allocation of resources not only for China, but also for other developing countries with a rapidly growing cardiovascular disease burden, limited medical resources, and dynamic health care systems.

Corresponding Author: Lixin Jiang, MD, PhD, National Clinical Research Center of Cardiovascular Diseases, Fuwai Hospital, National Center for Cardiovascular Diseases, 167, Beilishi Road, Xicheng District, Beijing, 100037, China (jianglixin@fuwai.com).

Accepted for Publication: December 23, 2015.

Published Online: March 14, 2016. doi:10.1001/jamainternmed.2016.0166.

Author Contributions: Drs Zheng and Curtis contributed equally to the study and are joint first authors; Drs Krumholz and Jiang contributed equally to the study and are joint senior authors. Dr Jiang had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Zheng, Curtis, Masoudi, X. Li, J. Li, Dharmarajan, Krumholz, Jiang.

Acquisition, analysis, or interpretation of data: Zheng, Curtis, Hu, Wang, Yang, Spertus, X. Li, Dharmarajan, Downing, Jiang.

Drafting of the manuscript: Zheng, Curtis, Hu.

Critical revision of the manuscript for important intellectual content: Zheng, Wang, Yang, Masoudi, Spertus, X. Li, J. Li, Dharmarajan, Downing, Krumholz, Jiang.

Statistical analysis: Hu, Wang, X. Li.

Obtained funding: Jiang.

Administrative, technical, or material support: Yang, X. Li, J. Li, Jiang.

Study supervision: Wang, Krumholz, Jiang.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Drs Curtis, Dharmarajan, and Krumholz reported working under contract with the Centers for Medicare & Medicaid Services to develop and maintain performance measures. Dr Masoudi reported having a contract with the American College of Cardiology as the senior medical officer of the National Cardiovascular Data Registries. Dr Dharmarajan reported being a paid member of a scientific advisory board for Clover Health. Dr Krumholz reported being a recipient of research agreements from Medtronic and from Johnson & Johnson through Yale University to develop methods of clinical trial data sharing and being paid chair of a cardiac scientific advisory board for UnitedHealth. No other disclosures were reported.

Funding/Support: This project was supported in part by grant 201202025 from the Research Special Fund for Public Welfare Industry of Health from the National Health and Family Planning Commission of China, and the National Key Technology R&D Program (2013BAI09B01) from the Ministry of Science and Technology of China. Drs Curtis and Krumholz are supported by grant U01 HL105270-05 (Center for Cardiovascular Outcomes Research at Yale University) from the National Heart, Lung, and Blood Institute. Dr Dharmarajan is supported by grant K23AG048331 from the National Institute on Aging and the American Federation for Aging Research through the Paul B. Beeson Career Development Award Program.

Role of the Funder/Sponsor: The Chinese government, which provided financial support for the study, and the other organizations providing support, had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Group Information: The members of the China PEACE Collaborative Group are listed in eAppendix 1 in the Supplement.

Additional Contributions: We appreciate the multiple contributions made by study teams at National Clinical Research Center of Cardiovascular Diseases and the Yale-New Haven Hospital Center for Outcomes Research and Evaluation in the realms of study design and operations, particularly the data collection by Yi Pi, MD, Jiamin Liu, MD, MS, Wuhanbilige Hundei, MD, Yang Yang, BS, Li Li, MD, MS, Fang Feng, MD, Haibo Zhang, MD, MS, Lihua Zhang, MD, PhD, Xue Du, MD, Wenchi Guan, MD, Xuekun Wu, MD, Yuan Yu, MD, Zhan Gao, MD, PhD, and Yuanlin Guo, MD, PhD. No financial compensation was provided.