I recently presented a morning report in my Clinic about preventive Cardiology...and I had mentioned about 'plumbing paradigm' ( relieving coronary blockage whenever we find one) does not make things better compared to a medical & lifestyle approach. I based this on two studies done on patients with stable coronary artery disease -
1.COURAGE trial - 2200 patients with stable CAD(ST depression or T wave inversion on resting ECG, inducible ischemia with exercise, or at least one coronary artery stenosis of at least 80% and angina. EF <30were excluded ). 2/3rds of pts had multivessel disease. Pts were randomised to PCI with bare metal stent Vs medical therapy. Over a period of nearly 5 years..there was no difference in primary outcome of all cause mortality, non fatal MI between 2 groups. Angina relief , stroke, hospitalisation for MI did not differ as well. But..a subgroup(n=314) were further enrolled to undergo nuclear study at baseline and after 1 year. PCI did show a significant reduction in ischemic myocardium compared to medical therapy.
2. BARI 2 trial - 2300 patients with type 2 diabetes and CAD(>50% stenosis of major coronary artery with +ve stress test or >70% stenosis with classic angina. Class 3 & 4 heart failure, creatinine>2 were excluded).Over a period of 5 years there was no significant difference between PCI/CABG Vs medical therapy alone ...in terms of survival, MI, and angina.
But ..recently ..the MASS 2 trial was published in Circulation - a randomised controlled trial of 611 patients with CAD ( with proximal multivessel stenosis .70%, stable class 2 or 3 CHF, HTN or diabetes). Pts were randomised to either CABG or PCI with BMS or medical therapy alone. Follow up for 10 years showed a significant improvement in cardiovascular mortality, recurrent MI, angina ...compared to medical therapy.PCI was associated with an increased need for further revascularization, a higher incidence of myocardial infarction, and a 1.46-fold increased risk of combined events compared with CABG. A thing to note..is that majority of patients in this study had aither triple vessel disease or proximal LAD disease....and this is likely why CABG showed a great benefit.
So.....based on these studies.....PCI /CABG may be superior to medical therapy in patients with stable multivessel disease( and the plumbing paradigm seems to work). But this cannot be generalized for others with stable and mild CAD ..where medical therapy has equal mortality and antianginal benefit as intervention...provided the disease is stable.