The American College of Cardiology’s (ACC) 61st annual scientific sessions began on March 24 and are currently underway through March 27 in Chicago. Here, we summarize some of the most compelling research to date including updates to CPORT-E, on-pump vs. off-pump CABG results, the use of CCTA in the emergency department, and two-year outcomes from transcatheter aortic valve replacement (TAVR).
Elective PCI safe without surgery back-up
The CPORT-E trial examined outcomes of performing elective PCI without surgical backup as compared to hospitals with cardiac surgery. Results suggest similar patient outcomes regardless of the presence or absence of surgery on site (SOS). Specifically, major adverse cardiac events suggested non-inferiority of PCI without SOS, with rates of 12.1% as compared to 11.2% with SOS (p=0.05). Similarly, mortality rates over six weeks were 1.0% and 0.9%, respectively (p=0.004). However, there was a higher rate of target-vessel revascularization at centers without SOS.
Authors suggest this could possibly be a result of the more conservative approach to PCI at centers without surgical back-up and greater use of bare metal stents. These findings are in accordance with the recently released ACC/AHA guidelines that support elective PCI at non-cardiac surgery centers. The authors were careful to conclude that these results do not suggest that PCI without SOS should proliferate and that programs must still take a strategic approach to offering high-quality service.
No significant differences in off-pump vs. on-pump CABG
The debate over off- pump and on-pump CABG is still underway as trials and meta-analyses have shown conflicting results. The CORONARY trial aimed to close the debate as the largest trial of its kind to review the outcomes of off-pump CABG to on-pump CABG across nearly 5,000 patients at 80 centers in 20 countries. Results showed no significant difference in 30-day outcomes for the primary end point, a composite of death, MI, stroke, or new renal failure requiring dialysis at 30 days after randomization. However, there were some differences in secondary end points. Those receiving off-pump CABG showed less bleeding, respiratory infections, and acute kidney injury, with fewer grafts and more revascularization.
The authors are continuing to follow patients for five years and plan to report again on long-term findings. In addition, the authors note differences may exist due to region (most CABGs are done on-pump in the U.S. and Europe) and operator experience. The results of the CORONARY trial do not align with the Cochrane review covered in the Cardiovascular Roundtable’s blog on Friday, March 23 which suggested a higher death rate with off-pump CABG.
CCTA in the ED safely discharges patients with shorter length of stay
The ACRIN-PA trial was a multicenter, randomized controlled study conducted by the American College of Radiology Imaging Network to examine if coronary CT angiography (CCTA) can be used to discharge low- and intermediate- risk patients (about 50%-70% of patients presenting with chest pain) from the emergency department. 1,370 patients presenting to the ED with the potential of ACS were randomized to 64-slice CCTA or traditional rule out (composed of diagnosis and care determined by a physician).
The CCTA group discharge to home rate was about 50% as compared to the traditional-care group discharge rate of approximately 23%. The CCTA group also had a shorter average hospital stay of 18 hours as compared to 25 hours. The coronary disease detection rate was higher in the CCTA group than the traditional rule out group (9.0% vs 3.5%, respectively). Each group experienced one myocardial infarction within 30 days of presentation. The authors conclude that the safety of this approach is "within a threshold that most emergency-department physicians would find acceptable."
Two-year outcomes for transcatheter valve replacement
The two-year results for Cohort A of the PARTNER trial illustrated long-term outcomes after transcatheter aortic valve replacement in high-risk patients. Both the transfemoral (48% of patients) and transapical approaches were used (52% of patients). After two years, half of the 339 patients followed were no longer living, but this rate did not differ from standard aortic valve surgery. The predictors of mortality were primarily unrelated to cardiac conditions, but were often due to co-morbidities such as chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), atrial fibrillation and frailty. Notably, the rate of paravalvular regurgitation was more common in patients receiving transcather valves. The results of this study suggest that these patient warrant close evaluation and follow-up.
In addition, an examination of Cohort B (patients ineligible for surgery) suggested that reduction in death and hospitalization, and improved symptoms were sustained for two years. At two years, 68% of patients receiving standard of care were no longer living, compared with 43% who had received transcather valve replacement.