Abstract
Background
Anomalies of the origin and course of the circumflex artery are amongst the most common seen at coronary angiography. There is limited information regarding patient and procedural characteristics, technical feasibility and outcomes associated with percutaneous intervention (PCI) to these vessels. The aim of this study is to examine our experience with PCI to anomalous circumflex vessels and compare this to some aspects of percutaneous intervention on non-anomalous circumflex vessels.
Methods
Over a 41 month period, 20 PCI procedures on anomalous circumflex vessels were identified and 1550 PCI procedures on non-anomalous circumflex arteries.
Results
In 9 anomalous cases, the circumflex arose from the left coronary cusp, in 7 cases from the right coronary cusp, and in the remaining 4 cases from the proximal right coronary artery. There were no differences in demographics or pattern or severity of coronary disease between the 2 groups. A higher proportion of patients with anomalous vessels presented acutely. Screening times were longer in the anomalous group. All 20 procedures were associated with immediate procedural success. There was one peri-procedural myocardial infarction unrelated to anomalous circumflex intervention. After a median follow-up period of 7.3 months, the only major adverse cardiac event recorded in the anomalous group was an ischaemia-driven revascularisation to a non-target vessel branch. We describe techniques which can be used to improve support and facilitate successful PCI to anomalous circumflex vessels.
Conclusion
PCI to anomalous circumflex vessels may be technically challenging, but is feasible and carries favourable short and long-term clinical outcomes.
Summary
This single centre observational study demonstrates that percutaneous coronary intervention to anomalous circumflex coronary arteries although technically challenging can be performed with satisfactory procedural success rates and favourable short and longer-term clinical outcomes. It describes various techniques that can be employed to optimise successful intervention.
1
Background
Coronary artery anomalies identified during coronary angiography are uncommon, with an estimated incidence of approximately 1% . A coronary anomaly is defined as an artery with an anatomical configuration rarely seen in the general population . Anomalies of the origin and course of the circumflex coronary artery are amongst the most frequently encountered and have been recognised as long ago as the 1930’s . The circumflex artery normally arises from the left coronary artery and passes within the atrio-ventricular groove posteriorly providing blood supply to the postero-lateral myocardium. It gives rise to marginal branches as it courses posteriorly terminating as the posterior left ventricular branch. In approximately 10% of cases it will also supply the posterior descending artery. Two equally common anomalies of the circumflex artery are recognised: a vessel arising from a separate origin within the left coronary cusp (LCC) ( Fig. 1 ) and one arising from the right coronary cusp (RCC), either directly ( Fig. 2 ), or as a branch from the right coronary artery (RCA) ( Fig. 3 ) . Whilst an anomalous circumflex vessel arising from a separate origin within the LCC follows a very similar course to the normal anatomical pattern, an anomalous circumflex vessel arising from the RCC or RCA invariably follows a retro-aortic course. This latter anomaly has been associated with an increased incidence of atherosclerosis and myocardial infarction in the presence of an angiographically patent vessel .
Anomalies of the circumflex artery pose several potential challenges to the interventional cardiologist. The anomalous vessel may be difficult to find or to selectively cannulate. Poor catheter seating may lead to inadequate visualisation of the vessel or may hamper attempts at advancing guide wires, balloons or stents to the desired location within the vessel. Whether these potential technical challenges impact immediate success rates and/or short or long term outcomes following percutaneous coronary intervention (PCI) has not been adequately addressed in previous studies, and this represents the aim of this report.
2
Methods
The Manchester Heart Centre is a tertiary cardiac centre performing in excess of 2000 PCI procedures annually. All patients undergoing PCI to the circumflex coronary artery over a 3½ year period (April 2004–September 2007) were identified from the cardiac database (CARDEX) in which procedural and clinical demographic data are entered for each patient undergoing PCI prospectively. Data quality entered into the CARDEX system is cross checked and validated by an independent Clinical Information Assistant using the PCI procedural reports generated by the operator and information obtained from the medical notes. Patient demographics, procedural details and clinical outcomes were obtained from the CARDEX system and the hospital’s electronic database which includes outpatient clinic letters and discharge summaries of subsequent hospital admissions. Long term end points were collected from outpatient clinic records. Post procedural clinic visits are standard of care in our institution. During these consultations any major events including hospitalisations in other institutions were also identified.
From the above, we were able to divide procedures into 2 groups: PCI to anomalous and PCI to non-anomalous circumflex vessels. The angiographic films of the former group were reviewed.
The Chi squared test was used to compare categorical variables. Continuous data were tested for normality using the Kolmogorov–Smirnov test. The Student’s independent 2-tailed t-test and Mann–Whitney tests were used to test for differences between groups in parametric and non-parametric data respectively. A p value of less than 0.05 was considered to be significant.
A major adverse cardiac event (MACE) was defined as death, myocardial infarction, stroke or ischaemia driven revascularisation. Myocardial infarction (MI) was defined as the presence of a typical history or electrocardiographic (ECG) changes and a rise in troponin above the reference limit of the biochemistry laboratory. A peri-procedural MI was defined as a rise in troponin 3 times greater than the reference limit.
Cerebrovascular accident was defined as a persistent focal neurological deficit present for greater than 24 h with associated new lesion on brain imaging.
Ischaemia-driven revascularisation was defined as either a PCI or coronary artery bypass graft (CABG) operation precipitated by an unplanned hospital admission due to a cardiac cause with either symptoms typical of myocardial ischaemia, electrocardiographic changes or a positive myocardial stress test for ischaemia.
2
Methods
The Manchester Heart Centre is a tertiary cardiac centre performing in excess of 2000 PCI procedures annually. All patients undergoing PCI to the circumflex coronary artery over a 3½ year period (April 2004–September 2007) were identified from the cardiac database (CARDEX) in which procedural and clinical demographic data are entered for each patient undergoing PCI prospectively. Data quality entered into the CARDEX system is cross checked and validated by an independent Clinical Information Assistant using the PCI procedural reports generated by the operator and information obtained from the medical notes. Patient demographics, procedural details and clinical outcomes were obtained from the CARDEX system and the hospital’s electronic database which includes outpatient clinic letters and discharge summaries of subsequent hospital admissions. Long term end points were collected from outpatient clinic records. Post procedural clinic visits are standard of care in our institution. During these consultations any major events including hospitalisations in other institutions were also identified.
From the above, we were able to divide procedures into 2 groups: PCI to anomalous and PCI to non-anomalous circumflex vessels. The angiographic films of the former group were reviewed.
The Chi squared test was used to compare categorical variables. Continuous data were tested for normality using the Kolmogorov–Smirnov test. The Student’s independent 2-tailed t-test and Mann–Whitney tests were used to test for differences between groups in parametric and non-parametric data respectively. A p value of less than 0.05 was considered to be significant.
A major adverse cardiac event (MACE) was defined as death, myocardial infarction, stroke or ischaemia driven revascularisation. Myocardial infarction (MI) was defined as the presence of a typical history or electrocardiographic (ECG) changes and a rise in troponin above the reference limit of the biochemistry laboratory. A peri-procedural MI was defined as a rise in troponin 3 times greater than the reference limit.
Cerebrovascular accident was defined as a persistent focal neurological deficit present for greater than 24 h with associated new lesion on brain imaging.
Ischaemia-driven revascularisation was defined as either a PCI or coronary artery bypass graft (CABG) operation precipitated by an unplanned hospital admission due to a cardiac cause with either symptoms typical of myocardial ischaemia, electrocardiographic changes or a positive myocardial stress test for ischaemia.
3
Results
3.1
Incidence
Over a 41 month period, 1570 circumflex PCIs were performed, of which 20 procedures (1.3%) were on anomalous vessels.
3.2
Baseline characteristics
There were no significant differences in baseline characteristics between the two groups ( Table 1 ).
| Anomalous Circumflex n = 20 | Non-anomalous Circumflex n = 1550 | P value | |
|---|---|---|---|
| Age (years) | 58.9 | 62.3 | ns |
| Male (%) | 75 | 75 | ns |
| BMI a | 27.3 | 28.3 | ns |
| Current Smoker (%) | 30 | 43 | ns |
| Previous MI b (%) | 6 | 24 | ns |
| Previous CABG c (%) | 5 | 7 | ns |
| Hypertension (%) | 40 | 42 | ns |
| Diabetes (%) | 10 | 20 | ns |
| Peripheral Vascular Disease (%) | 5 | 13 | ns |
| Cerebrovascular Disease (%) | 5 | 6 | ns |
| Renal Impairment (%) | 0 | 2 | ns |
| Hypercholesterolaemia (%) | 67 | 77 | ns |
3.3
Mode of presentation
There were significantly more acute presentations in the anomalous group compared with the non-anomalous group (80% vs 46%, p = 0.018; Table 2 ). In the anomalous group, 5 patients presented with stable angina and underwent elective PCI, 10 patients presented with non-ST elevation myocardial infarction (NSTEMI) and had PCI during the index admission and 5 patients had PCI in the context of ST-elevation myocardial infarction (STEMI) (2 as primary PCI, and 3 following failed thrombolysis).
| Anomalous circumflex n = 20 | Non-anomalous circumflex n = 1550 | P value | |
|---|---|---|---|
| Acute Presentation (%) | 80 | 46 | .018 |
| Cardiogenic Shock (%) | 0 | 1 | ns |
| Radial Approach (%) | 15 | 21 | ns |
| LMS a Disease (%) | 0 | 3 | ns |
| LAD b Territory Disease (%) | 35 | 50 | ns |
| RCA c Territory Disease (%) | 55 | 43 | ns |
| 3 Vessel Disease (%) | 20 | 24 | ns |
| 3 Vessel Disease or LMS (%) | 20 | 26 | ns |
| Mean Number of Vessels Diseased | 1.90 | 1.93 | ns |
| Mean Number of Lesions Treated | 2.05 | 2.09 | ns |
| Exposure Time (min) | 24.4 | 18.5 | .02 |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
