Is long term survival comparable PCI vs CABG?
Over the last 25 years there has been a dizzying array of studies comparing PCI vs CABG allowing in turn for varying interpretations and recommendations.
A) Overall 10 year survival PCI vs CABG
A comparison of extended long term survival
i.e. comparison of survival at 15 years or more is simply not available. However for the first time a comparison of ten year survival PCI vs CABG was recently published in JACC (Journal of American College of Cardiology.) The authors evaluated 2240 patients who underwent CABG or PCI from the year 2000 – 2006. Even with the use of the outdated first generation DES (drug eluting stent) the survival of patients who underwent PCI for Multi-vessel CAD including Left Main blockages was comparable with patients who underwent surgery.
Well over 30% of the patients in this trial were Diabetics.
Even before the introduction of Coronary stents PCI in the form of Plain Old Balloon Angioplasty demonstrated equipoise with CABG at 10 years except in diabetics. (BARI trial)
B) Overall 3 – 5 year survival PCI vs CABG
Survival at 3- 5 years has been looked at in multiple studies over at least the last 20 years.
These studies include BARI, RITA, ACME, MASS, AVERT, TIME, SYNTAX 1, SYNTAX 2, EXCEL and NOBLE amongst others.
In general the 3-5 year survival with CABG and PCI in patients with Multi-vessel CAD including Left Main Coronary artery disease is comparable except in diabetics and in patients with a high Syntax score.
C) Overall 5-8 year survival PCI vs CABG in diabetics
In Diabetics with multi vessel CAD in general the 5 year survival with CABG is superior to PCI.
More recently FREEDOM trial has looked at 8 year survival in diabetics undergoing surgery vs PCI claiming superiority with a surgical approach.
However the results of this trial are being challenged by several investigators:
1) Speaking at the 2018 annual sessions of American heart association where findings of the FREEDOM trial were presented, experts noted that 1 million coronary revascularization procedures are performed each year, with 35% done in patients with diabetes. It was also noted that despite the randomized nature of the trial, bias was possibly introduced with just under half of patients followed and that the follow up study is also likely underpowered.
2) In an editorial accompanying the study published in the Journal of American College of Cardiology, several other experts questioned the reliability of the mortality benefit in FREEDOM trial.
They point out that just 16 more deaths in the CABG arm would have rendered the between-group difference statistically nonsignificant.
3) Additionally, they suggest that data from more recent clinical trials and registries has shown even more improved results with new -generation drug -eluting stents.
4) Interestingly, a recent individual patient data pooled analysis of 11 RCTs (randomized controlled trials) published in JACC in 2018 demonstrates a significantly greater risk of stroke after CABG especially in patients with diabetes and Multi-vessel CAD.
The five year mortality was significantly higher for patients experiencing a stroke within 30 days after revascularization.
D) 5 Year Survival very high Syntax score PCI vs CABG
The 5 year outcomes can also vary depending upon complexity of CAD as determined by the SYNTAX score; A very high Syntax score favors surgery.
CABG may offer better 5 year survival rates in diabetics with triple vessel CAD but in most studies comparing CABG Vs PCI for Multi-vessel CAD there was an initial higher peri-operative mortality and stroke rate with CABG. There was also a much higher rate of arrhythmias including atrial fibrillation with surgery.
Both major stroke and cardiac arrhythmias like atrial fibrillation translate into major long term debility and the accompanying lifestyle issues.