Impact of the introduction of drug eluting stents on clinical outcomes in patients undergoing percutaneous and surgical coronary artery revascularisation procedures in Western Australia

Temporal trends in percutaneous coronary intervention in Australia: A retrospective analysis from 2000-2021

OBJECTIVE

The aim of this study was to describe the trend in percutaneous coronary intervention (PCI) with insertion of a stent in Australia from 2000/01 to 2020/21 and investigate trends in same-day versus non-same-day discharge following PCI. A secondary aim was to compare the rate of coronary artery bypass grafting (CABG) with PCI procedures, while a third aim was to compare marked PCI trend changes with the PCI guidelines during the study period.

BACKGROUND

PCI with stent deployment is the most common form of interventional treatment for coronary artery disease, and its use has been expanding since 2000. However, there is a lack of descriptive studies of the national trend in Australia.

METHODS

All procedures for PCI and CABG were extracted across 21 years (2000/01 to 2020/21) from the Australian Institute of Health and Welfare data. Age-standardized rates were calculated using the Australian standard population as of June 2001. The ratio of PCI to CABG procedures was also calculated. Trends for PCI were stratified by age, gender, and same-day or overnight discharge episodes. Linear regression analysis was done to compare the age-standardized rates across different age categories. Segmented regression analysis was performed to ascertain the change in the age-standardized rates of PCI during the study period. Whether the changepoints in the trend were matched with guideline updates was also assessed.

RESULTS

There were 751 728 PCI procedures in persons aged 30 years and above between 2000/01 and 2020/21. The age-standardized rate for the study period showed that persons aged 60-74 years had a higher rate of procedures (102.7) compared to persons aged 30-59 years (81.3) and 75 years and older (61.8) (P < 0.001). There were two statistically significant changepoints in the overall trend; 2005/06 and 2013/14, matched with the change in PCI guidelines. Despite the lower number of procedures for same-day discharge episodes, there has been an increasing trend since 2014/15. More than two-thirds of all stenting procedures were the insertion of a single stent. PCI to CABG procedure ratio increased from 0.6 in 2000/01 to 1.8 in 2020/21.

CONCLUSIONS

There was a varying trend in the age-standardized rate of PCI with a peak in 2005/06. The trend appears to be stabilizing in the later part of the study period, but the rate for same-day discharge episodes showed an increasing trend after 2014/15. There is consistency with changepoints in the trend and updated PCI guideline recommendations. The ratio of PCI with insertion of a stent to CABG procedure increased substantially across the study period.

Is the incidence of heart attack still decreasing in Australia? Developing reliable methods for monitoring trends in myocardial infarction and coronary heart disease (AUS-MOCHA): a study protocol

INTRODUCTION

Accurate monitoring of acute coronary heart disease (CHD) is essential for understanding the effects of primary and secondary prevention and for planning of healthcare services. The ability to reliably monitor acute CHD has been affected by new diagnostic tests for myocardial infarction (MI) and changing clinical classifications and management of CHD. Our study will develop new and reliable methods for monitoring population trends in incidence, outcomes and health service usage for acute CHD and chest pain.

METHODS AND ANALYSIS

The study cohort of all CHD will be identified from the Western Australian Data Linkage System using state-wide data sets for emergency department presentation, hospitalisations and mortality data for 2002-2014. This core linked data set will be supplemented with data from hospital medical record reviews, pathology data and hospital pharmacy dispensing databases. The consistency over time of the coding of the different subgroups of CHD/chest pain (ST-elevation MI, non-ST elevation MI, unstable angina, stable angina, other CHD, non-CHD chest pain) in linked data will be assessed using these data sources, and an algorithm developed detailing groups in which temporal trends can be reliably measured. This algorithm will be used for measurement of trends in incidence and outcomes of acute CHD, and to develop further methods for monitoring acute CHD using unlinked and linked data with varying availability of hospitalisation history.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Human Research Ethics Committees of the WA Department of Health (#2016/23) and The University of Western Australia (RA/4/1/7230). Findings will be disseminated via publication in peer-reviewed journals, and presentation at national and international conferences. There will also be a strong platform for dissemination of new monitoring methods via collaboration with the Australian Institute of Health and Welfare which will assist with promotion of these methods at state and national levels.

Evaluation of long-term clinical and health service outcomes following coronary artery revascularisation in Western Australia (WACARP): a population-based cohort study protocol

INTRODUCTION

Coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI) are procedures commonly performed on patients with significant obstructive coronary artery disease to relieve symptoms of ischaemia, improve survival or both. Although the efficacy of both procedures at the individual level has been established, the impact of advances in coronary artery revascularisation procedures (CARP) on long-term outcomes and cost-effectiveness at the population level are yet to be assessed. Our aim is to evaluate a minimum of 6-year outcomes and costs for the total population of patients who had CARP in Western Australia (WA) in 2000-2005.

METHODS AND ANALYSIS

This retrospective population cohort study will link clinical and administrative health data for a previously defined cohort including all patients in WA who had a CARP in the period 2000-2005. The cohort consists of 19,014 patients who had 21,175 procedures (15,429 PCI and 5746 CABG). We are now collecting a minimum of 6 years follow-up of morbidity and mortality data for the cohort using the WA Data Linkage System, clinical registries and hospital records, with 12 years follow-up for cases in the year 2000. Comparison of long-term outcomes for different CARP will be reported (PCI vs CABG; bare metal stents vs drug-eluting stents vs CABG). Cost-effectiveness analysis of CARP from the perspective of the healthcare sector will be performed using individual level cost data and average costs from Australian Refined Diagnosis Related Groups.

ETHICS AND DISSEMINATION

This study has received ethics approval from the University of Western Australia, the Western Australian Department of Health and all participating hospitals. Being a large population cohort study, approval included a waiver of informed consent. All findings will be presented at local, national and international healthcare/academic conferences and published in peer-reviewed journals.