Congenital Coronary Artery Anomalies and Outcomes in Patients Undergoing Percutaneous Coronary Interventions – A Matched Analysis of a Large National Database.

Background
There is limited data on the outcomes of percutaneous coronary intervention (PCI) in patients with congenital anomalous coronary arteries (ACA). Our study evaluates the clinical outcomes of PCI in this patient population.

Methods
We queried the Nationwide Inpatient Survey Database over a 16 year period from 1998-2013 and defined our study population as patients who underwent a PCI who had a diagnosis of anomalous coronary arteries using ICD-9 codes. We performed a 1:1 case control matching [controls matched to cases based on traditional coronary artery disease (CAD) risk factors – age, gender, smoking, diabetes, hypertension, and race/ethnicity]. We described the baseline characteristics, use of intra-operative diagnostic modalities and in-hospital outcomes.

Results
Our analysis 2,636 patients who had a documented anomalous coronary artery. We used 2,131 cases [PCI + ACA ] that were matched with another 2,131 controls [PCI without ACA]. Overall, we found fewer PCIs in ACA patients above the age of 80 (9.0% vs 12.3%; p<0.001). More Non-ACA patients presented with acute MI (65.5% vs 45.2%; p<0.001) . The ACA cohort were more likely to receive a bare metal stent (38.4% vs 29.6%; p<0.001]; undergo CABG [1.5% vs 0.8%; p 0.062]; require IVUS [7.6% vs 3.9%; p<0.001]; develop sinus node dysfunction [1.3 vs 0.5%; p=0.003]; require temporary pacemakers [2.4% vs 1.4%; p=0.016].

Chronic total occlusion (11.5% vs 6.4%; p<0.001), coronary artery dissection (29.1% vs 17.3%; p<0.001) and in-hospital cardiac arrest [1.5% vs 3.1%; p<0.001] were less frequent ACA patients. Length of stay (days) was shorter in the ACA patients [3.0 (SD 3.5) vs 4.0 (SD 5.9); p<0.001] . Mortality was higher among the non-ACA patients compared with ACA patients (1.9 vs 1.0; p=0.016).

Conclusions
ACA are uncommon among patients undergoing PCI. Patients with ACA have a more benign prognosis with lower complication and mortality rates. ACA patients are more likely to undergo intraprocedural coronary imaging, and receive a bare metal stent. Reasons for the differences in outcomes and hospital management of ACA patient deserve further study to determine whether or not non-ACA patients have a higher burden of coronary disease.