PCI is effective in relieving angina, what does it do to LV dysfunction?
This is a fundamental query in the principles of revascularisation of CAD . The term LV dysfunction can convey a bizarre meaning.It can constitute any of the combinations of the following.Cell death, necrosis, scarring, fully dead, partially dead, partially viable, apoptotic cells that are clustered across various myocardial segments. These cells are interwoven with fibrotic interstitium. Microvascular integrity is also altered.
Cells stretch, slip and slide with one another. Contractile architecture is lost. This is referred to as remodeling.In the process, the ventricle gets dilated. Wall stress increases, LVEDP raises. Patient may go for progressive failure.The whole concept of chronic myocyte loss is due to the process called programmed cell death.
Does PCI cancel this pre-planned program?
The answer seems to be a clear ” No” (Of course few studies do show some improvement ) It is becoming clear, chronic ischemic juggernaut moves on. The mechanical spiral effect on the myocardium will go unabated whether you rectify the small residual ischemia or not), However, tissue engineering, anti-fibrotic drugs, cell repair molecules, stem cell assistance are attractive approaches to prevent or treat ischemic cardiomyopathy in the future.
If PCI can’t do it what about CABG ?
Read the STICH trial in Ref 2
Point of clarification
Revascularisation does have a role in salvaging the myocardium and improves LV function when done before irreversible damage has happened. When does it happen? To be precise, within 24 hrs of IRA occlusion. This is all about knowing the science of myocardial viability. Of course, In (un)real world this 24 h deadline is the least respected time window because cath lab viability directly competes with myocardial.
Reference
Dr.S.Venkatesan MD 