Chest pain remains one of the most frequent presenting complaints in clinical practice, with a substantial proportion of patients demonstrating significant cardiovascular risk factors warranting further assessment. Despite advances in non-invasive imaging, invasive coronary angiography continues to represent the gold-standard investigation for definitive evaluation of coronary artery disease. However, contemporary data describing the safety of elective diagnostic coronary angiography are limited. Most published series have combined elective and inpatient cases, introducing potential confounders such as acute coronary syndromes, decompensated heart failure, ventricular arrhythmias, acute kidney injury, and other concurrent illnesses. As such, true complication rates among stable, elective cases in modern practice remain uncertain. This study therefore aims to define the current peri-procedural complication rates associated with elective diagnostic coronary angiography in a contemporary, real-world New Zealand cohort, and to describe the frequency and outcomes of ad hoc percutaneous coronary intervention performed during these procedures.

This was a retrospective observational study utilising data from the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry, which captures more than 95% of all coronary angiography procedures performed nationally. Ethics approval was obtained prior to data extraction. All records were handled by an independent biostatistician using de-identified unique identifiers to ensure patient confidentiality. Data from September 2014 to August 2022 were reviewed. Only elective diagnostic coronary angiograms and ad hoc percutaneous coronary interventions (PCI) performed during the same session were included. All inpatient procedures and planned PCI cases were excluded to minimise confounding from acute or unstable clinical conditions. The primary outcomes were index-episode death, index-episode stroke, and a composite of death or stroke. Secondary outcomes included overt bleeding events (Bleeding Academic Research Consortium [BARC] type 3 or 5), vascular complications requiring intervention, and emergency coronary artery bypass grafting. Descriptive statistics were used to summarise patient and procedural characteristics, with complication rates reported as proportions of total procedures.

A total of 29,177 elective coronary angiograms were analysed between September 2014 and August 2022, comprising 25,272 diagnostic procedures (86.6%) and 3,905 ad hoc percutaneous coronary intervention (13.4%). The mean age was 66.7 ± 10.4 years, and 66.6% were male. The majority were of European/Other ethnicity (76.2%), with Māori (10.9%), Pacific (4.7%), and Asian (8.2%) patients also represented. Radial access was used in 89% of angiograms and 92% of ad hoc percutaneous coronary interventions. The primary indications were suspected or known coronary artery disease (69.6%) and primary valve disease (18.8%). The overall rate of index-episode death was 0.04%, stroke 0.12%, and the composite of death or stroke 0.13%. Among diagnostic angiograms alone, rates were 0.03%, 0.12%, and 0.12% respectively; in ad hoc percutaneous coronary intervention, 0.15%, 0.10%, and 0.20%. Secondary outcomes were rare: overt bleeding (BARC ≥ 3) 0.06%, vascular complications requiring intervention 0.03%, and emergency coronary artery bypass grafting 0.02%. Most vascular complications were femoral pseudoaneurysms; bleeding events were mainly BARC 3a/b, with one BARC 5 event. Radial access was associated with numerically lower adverse events compared with femoral access (death 0.04% vs 0.06%, stroke 0.10% vs 0.25%, composite 0.10% vs 0.25%; bleeding 0.02% vs 0.31%; vascular intervention 0.01% vs 0.17%). Overall procedural complication rates were extremely low across all subgroups, confirming the excellent safety profile of elective diagnostic coronary angiography in contemporary New Zealand practice.

In this large, contemporary national cohort, elective diagnostic coronary angiography was associated with exceptionally low rates of major peri-procedural complications. Index-episode death, stroke, and the composite endpoint occurred in fewer than 0.2% of cases, and secondary events such as bleeding, vascular injury, or emergency coronary surgery were exceedingly uncommon. The predominance of radial access likely contributed to these excellent safety outcomes, with numerically lower complication rates compared with femoral access. These findings provide important real-world reassurance regarding the safety of elective coronary angiography in modern practice and establish national benchmarks for ongoing quality improvement across New Zealand cardiac catheterisation laboratories.