How to reduce mortality during complex angioplasty
When doing a complex Angioplasty, there is a risk of heart stopping for few moments, which can result in on-table death. During these moments of cardiac arrest, if blood supply to other vital organs like brain & kidney is maintained and if heart is prevented from ballooning out due to un-pumped blood - out of heart, then death can be averted.
Ballooned out heart generally doesn't recover, and cardiac arrest will become irreversible.
In this regard, options that can be considered to reduce mortality in high risk & complex angioplasty are:
1. IABP (Balloon pump) - by reducing the resistance to heart's pumping - allows more emptying of heart. Hence unloads heart (left ventricle)...help maintain circulation in slightly better way. Works best when heart is still working. Counterpulsation (mechanism of IABP) works when there is pulsation of heart and may not be effective in arrested heart.
2. ECMO. It's an external pump equipped with oxygenator. Generally a cannula is placed in artery and another in vein. Both are connected to ECMO circuit. This actively sucks the blood from veins, oxygenates and pushes back into arteries. This maintains the circulation and blood supply to vital organs during cardiac arrest or profound hypotension due to circulatory arrest. However it doesnot empty the heart, hence one has to keep doing chest compression to keep the heart empty and prevent from ballooning.
3. Impella: Impella is world's most miniature heart pump. It's inserted percutaneously into heart. It works like "water sump motor pump". It actively sucks the blood from heart and pumps into arterial circulation...or in other words it just works like our own heart. Thus it maintains circulation and also prevents heart from ballooning out. This is of immense use during high risk angioplasty where cardiac arrests will have very minimal impact on patient survival and patient's tolerability of procedure.
Below is an example of one such case.
This was one of the elderly lady in her 70's , who had bypass surgery done a decade back, now all her bypass grafts had blocked off completely...she has one native artery which is trying to supply the blood to entire heart through small collateral channels. And this artery has a critical block...which had lead to an heart attack 3-4 days back with near- cardiac arrest. Repeat bypass surgery was ruled out in view of poor target vessel. Only option left out was angioplasty. It was of high risk with inevitably high chance of cardiac arrest. Impella was used in this case...which maintained circulation so well and prevented heart from ballooning out when she had cardiac arrest during the procedure, that she didn't even realise any discomfort...she was conscious throughout, maintained BP well and sailed out with successful procedure. She was ambulated on next day and got discharged home within 72 hrs of procedure.
Dr. Srinivasa Prasad
Sr. Consultant Cardiologist
Fortis Hospital, BG Road
9901999409 / 8589922924.