Effects of left ventricular unloading on reperfusion-related AIVR in acute myocardial infarction

Surgical outcomes of bridge-to-bridge therapy with extracorporeal left ventricular assist device for acute myocardial infarction in cardiogenic shock

Background

Extracorporeal left ventricular assist device is often required for acute myocardial infarction patients in cardiogenic shock when temporary mechanical circulatory support fails to provide hemodynamic stabilization. This study aimed to evaluate the clinical outcomes of acute myocardial infarction patients in cardiogenic shock supported by an extracorporeal left ventricular assist device.

Methods

This retrospective study enrolled 13 acute myocardial infarction patients in cardiogenic shock treated with an extracorporeal left ventricular assist device from April 2011 to July 2020.

Results

Twelve (92.3%) and eleven (84.6%) patients were supported using venoarterial extracorporeal membrane oxygenation and intra-aortic balloon pumping before implantation, respectively. The median duration from acute myocardial infarction to extracorporeal left ventricular assist device implantation was 7 (3.5–24.5) days. The overall in-hospital mortality rate was 30.8% (n = 4). Extracorporeal left ventricular assist device was explanted in one patient for cardiac recovery; eight (61.5%) patients were approved as heart transplant candidates in whom the extracorporeal left ventricular assist device was exchanged for a durable left ventricular assist device; two (15.4%) expired while waiting for a heart transplant, and two (15.4%) received a successful transplant. The 1- and 3-year overall survival rates after extracorporeal left ventricular assist device implantation were 68.3% and 49.9%, respectively.

Conclusions

The operative mortality after extracorporeal left ventricular assist device implantation in acute myocardial infarction patients in cardiogenic shock was favorable. Our strategy of early hemodynamic stabilization with extracorporeal left ventricular assist device implantation in these patients as a bridge-to-bridge therapy was effective in achieving better survival.

Acute haemodynamic effects of accelerated idioventricular rhythm in primary percutaneous coronary intervention

AIMS

Accelerated idioventricular rhythm (AIVR) is very frequently observed in primary percutaneous coronary intervention (PCI), however knowledge of the haemodynamic effects is lacking.

METHODS AND RESULTS

We studied an ST-segment elevation myocardial infarction cohort of 128 consecutive patients (aged 62±11 years) in whom AIVR occurred following reperfusion during primary PCI. Mean systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate were determined during periods of AIVR and sinus rhythm. We grouped patients according to the infarct-related artery and the site of the coronary occlusion. AIVR caused an immediate reduction in SBP (130±27 vs. 98±22 mmHg, p<0.001) and DBP (80±19 vs. 69±16 mmHg, p<0.001) and a small increase in heart rate (78±12 vs. 83±11 bpm, p<0.001) as compared to sinus rhythm, irrespective of infarct-related artery. Both absolute as well as relative reduction in SBP were more pronounced in distal than proximal left coronary artery (LCA) occlusions (36±16 vs. 27±12 mmHg, p<0.01, respectively 25±9 vs. 20±8%, p<0.05). These haemodynamic differences between proximal and distal occlusion sites were not observed in the right coronary artery.

CONCLUSIONS

AIVR following reperfusion is associated with marked reduction in both SBP and DBP, irrespective of infarct-related artery. These haemodynamic effects are accompanied by only a very modest increase in heart rate during AIVR. Patients with a culprit lesion in the proximal LCA showed a smaller reduction in systolic blood pressure than distal LCA lesions.