Courtesy of Dr. Carlos Fava.

The prevalence of cardiogenic shock in acute myocardial infarction (MI) is 7%-10%, and it is associated with high mortality rates. Unfortunately, 0.7% of these cases are a consequence of unprotected left main coronary artery (ULMCA) as MI-culprit lesion. Its evolution is generally disastrous.

Ventricular assist device support and its implementation time may improve the prognosis, but related information currently available is scarce.

This study analyzed 36 consecutive patients with MI-ULMCA culprit lesion in 19 sites that participated in the cVAD Registry. These patients received Impella 2.5 (Abiomed Inc, Danvers, MA) left ventricular assist device support.

Studied populations were similar: the average age was 69.8 years old (most patients were male), 26 patients were admitted with cardiogenic shock in the emergency department, almost half had sustained cardiac arrest, and a third had anoxic brain injury. In 20 patients, support was initiated before angioplasty.

Ejection fraction was 24.6% and the Society of Thoracic Surgeons Predicted Risk of Mortality was 23.1%; 12 patients presented cardiogenic shock of over 24 hours; 17 received an intra-aortic balloon pump, and most were being administered two inotropic agents.

Transference was faster in cases of patients who received Impella before angioplasty, and non-ST segment elevation MI was more frequent in that group. These patients also presented more coronary lesions ≥50% (2.4 vs. 1.8; p = 0.05) and stent implantation was more frequent (2.58 vs. 1.53; p = 0.006). Procedural time was 2.12 h and ventricular assist time was 23.3 h.

Early use of Impella 2.5 provided hemodynamic improvement and lowered the need for inotropic agents.

Global in-hospital complications were stroke (5.6%), acute renal failure (19.4%), bleeding requiring transfusion (2.8%), and vascular complications requiring surgery (2.8%). No differences were observed among groups.

Survival at discharge for the whole cohort was 38.9%, and it was better for patients who received early support (55% vs. 18%; p = 0.04).

At 30 days, survival was higher among patients who received Impella 2.5 before angioplasty (48.1% vs. 12.5%; p = 0,004).

Conclusion

Initiation of Impella 2.5 ventricular assistance prior to as compared with after angioplasty of MI-ULMCA culprit lesion is associated with significant early survival. As previously described, patients supported after angioplasty had worse rates of survival at 30 days.

Editorial Comment

While the number of patients involved is small, this is the first study analyzing cardiogenic shock in ULMCA, showing that early ventricular assistance with Impella is not only feasible and safe, but also a means of lowering the need for inotropic agents and 30-day mortality.

A limitation of this study is that this renowned device is not available in most cath labs all over the world. Furthermore, its cost is high and it is used in a significantly low number of research studies.

Courtesy of Dr. Carlos Fava.

Original title: Impella 2.5 Initiated Prior to Unprotected Left Main PCI in Acute Myocardial Infarction Complicated by Cardiogenic Shock Improves Early Survival.

Reference: Perwaiz M. Meraj, et al. J Interventional Cardiology 2017;30:256-63.

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