Interventional cardiology’s flag-bearing procedure primary PCI stands tall and is being projected to be the greatest thing to happen for the human heart during the critical times of STEMI. The aim is to do a fast PCI to salvage the myocardium. Unfortunately ,It has become a strange habit, (endorsed by even learned cardiology forums) to define the success of primary PCI based on the restoration of TIMI 3 flow in the IRA, and not on the amount of myocardium salvaged .
What is more worrisome is, the fact, that almost every experienced cardiologist knows, crystal clear, that there is a pitiful relationship between TIMI flows at the epicardial artery and subsequent LV function. Of course, it might improve as time goes on. Still, it is unacceptable to define success of pPCI prematurely. some times, as early as the patient is wheeled out of cath lab.
What does the evidence say ?
The incidence of moderate or severe LV dysfunction even after a timely pPCI is still significant. The average incidence hovers around 36% .It would mean , atleast one third of patients who undergo pPCI leave the hospital with significant myocardial damage, but the cath lab report would say proudly , it is a successful pPCI without any untoward events. (Mind you, in the strict sense, even treated no-reflow should come under partial failure of pPCI, which again constitutes another 20%) Ref : Papapostolou S, et al, A Long-term clinical outcomes of transient and persistent no-reflow following percutaneous coronary intervention (PCI): a multicentre Australian registry. EuroIntervention. 2018 Jun 20;14(2):185-193.
Comparative studies that looked into LV function following pPCI
| Study (Year, Location) | Sample Size | LV Dysfunction Definition | Incidence (%) | Key Predictors |
|---|---|---|---|---|
| Khaled et al. (2022, Saudi Arabia) | 2863 | LVEF ≤30% (early, <24h echo) | 36% | Anterior STEMI, high troponin, renal impairment, multi-vessel disease |
| Liu et al. (2023, China) | 186 | LVEF decline (long-term, 4y) | 54 % | High peak troponin I, anterior STEMI, prior MI, low baseline LVEF |
| Kim et al. (2018, Korea) | 1736 | LVEF ≤40% (3-12m echo) | 14% | Baseline LVEF ≤40%, renal insufficiency, high peak CK/CKMB |
| Parodi et al. (2007, Italy) | 500 | <40% (Variable) | 27-60% range cited | Anterior MI, large infarct size |
| HORIZONS-AMI (2011) | Large RCT | Heart failure post-PCI | 5-9% | Thrombus burden, delayed reperfusion |
Note a curious point : The HORIZONS-AMI had a very low incidence of LV dysfunction totally a disconnected with the reality
Final message
It is a height of deceit, when some of us are still canvasing patients, emphasizing , that it has 95% success, hiding behind the TIMI 3 flow at IRA. Still waiting for the day of reckoning (Read my 2016 presentation in CSI Kochi conference) when the ACC/ESC/SCAI , will ultimately redefine the definition of successful pPCI to include a cut off of post-procedure EF of at least 50%.
Let us not stop with that, we have to mitigate the LV dysfunction with all our might. This implies early preventive and protective measures to maintsin the microvascular integrity , which is responsible for this epicardial-myocardial dissociation.
Reference
- Khaled S, Shalaby G. Severe left ventricular dysfunction earlier after acute myocardial infarction treated with primary percutaneous coronary intervention: predictors and in-hospital outcome. A Middle Eastern tertiary center experience. J Saudi Heart Assoc. 2022;34(4):257-63. https://doi.org/10.37616/2212-5043.1325sha257-263.pdfj-saudi-heart
- Liu C, Guo M, Cui Y, Wu M, Chen H. Incidence and predictors of left ventricular function change following ST-segment elevation myocardial infarction. Front Cardiovasc Med. 2023;10:1079647. https://doi.org/10.3389/fcvm.2023.1079647pmc.ncbi.nlm.nih+1
- Kim DH, Park CB, Jin ES, Hwang HJ, Sohn IS, Cho JM, Kim CJ. Predictors of decreased left ventricular function subsequent to follow-up echocardiography after percutaneous coronary intervention following acute ST-elevation myocardial infarction. Exp Ther Med. 2018;15(5):4089-96. https://doi.org/10.3892/etm.2018.5962spandidos-publications+1
- Parodi G, Memisha G, Carrabba N, Signorini U, Migliorini A, Cerisano G, Bolognese L. Prevalence, predictors, time course, and long-term clinical implications of left ventricular functional recovery after mechanical reperfusion for acute myocardial infarction. Am J Cardiol. 2007;100(12):1718-22. https://doi.org/10.1016/j.amjcard.2007.07.022pubmed.ncbi.nlm.nih
- Kelly DJ, Gershlick T, Witzenbichler B, Guagliumi G, Fahy M, Dangas G, Lansky AJ, Mehran R, Stone GW; HORIZONS-AMI Trial Investigators. Incidence and predictors of heart failure following percutaneous coronary intervention in ST-segment elevation myocardial infarction: the HORIZONS-AMI trial. Am Heart J. 2011;162(4):663-70. https://doi.org/10.1016/j.ahj.2011.07.032pubmed.ncbi.nlm.nih+1
Dr.S.Venkatesan MD 