Cardiogenic shock in myocardial infarction with non-obstructive coronary arteries
Authors: Caldeira Da Rocha R , Claudio FC , Pais JP , Bras DB , Picarra BP 
Published: May 2022

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
Cardiogenic Shock(CS)complicates 10%of Acute Myocardial Infarction(AMI),being the main cause for intra-hospital death in these patients. Myocardial Infarction with Non-Obstructive Coronary Arteries-MINOCA-has up to 14% prevalence. In these cases,revascularization,which has contributed so much for survival increasement in CC due to AMI,is not the most adequate treatment.

Purpose
Characterize population of patients (pts)with CS after MINOCA and assess impact in mortality.

Methods
We evaluated 915pts presenting with CS in context of AMI.We considered 2 groups:Group 1-Pts with MINOCA and group 2-pts with AMI due to obstructive coronary disease.We registered age, gender,comorbidities,presentation and treatment strategies.We evaluated in-hospital mortality and complications:mechanical complications,high-grade atrioventricular block(AVB),sustained ventricular tachycardia,atrial fibrillation(AF),resuscitated cardiac arrest,stroke,major bleeding and performed blood transfusion.

Results
MINOCA presenting as Cardiogenic Shock was found in 10%of pts(n=91),of whom71% were male with a mean age of 70±10years old.Group 1 pts were more commonly non-smokers (15% vs 25%,p= 0.037;CI95%[1.03-3.50], had more previous valve disease and heart failure (respectively 10% vs 4%; p=0.035; CI95% [0.16-0.91] and 15% vs 9%,p=0.021;CI95%[0.24-0.91]).Distribution of other comorbidities was similar in both groups.AMI type and localization was not significantly different in CS groups. CS due to MINOCA(CSMIN) presented more often in CS at admission(76%vs 49%,p&lt;0.001;CI95%[0.18-0.52]) and group 2 evolved more often in CS during in-hospital period.Group 1 pts presented with higher creatinine at admission (1.4mg/dL(1.1;2.0) vs 1.2mg/dL(0.9; 1.6),p=0.012) and hemoglobin levels during in-hospital period (11.3±2 vs 10.8±2.1,p=0.038).They also had more thrombocytosis during this period of time(7%vs2.3%,p=0.040;CI95%[0.11-0.89]). Ejection fraction was similar in both pts (41%±14 vs 39%±13,p=0.291).Intra- aortic balloon and invasive and non-invasive mechanical ventilation were used less frequently in group 1 (0% vs 11%,p&lt;0.001;2% vs 30%,p&lt;0.001, and 1%vs16%,respectively).Inotropic drugs were administered equally in both groups(57%vs72%,p=0.063).
During in-hospital period,pts with CSMIN presented less frequently with arrhythmic events,such as AF(5% vs19%,p=0.002;CI95%[1.55-11.98]) and AVB(1.3%vs18.3%,p&lt;0.001). This group also had less resuscitated cardiac arrest events(13%vs24%,p=0.023;CI95%[1.10-4.31]),major bleeding(1.3%vs8.9%,p=0.021) and in-hospital death(20%vs36%,p=0.003;CI95%[1.29-3.87]).

Conclusion
Cardiogenic Shock in MINOCA was found in 10% of patients with Cardiogenic Shock. These had less comorbidities. They were submitted to organ support less oftenly and had fewer complications. Even though Cardiogenic Shock due to MINOCA was associated with one fifth of in-hospital mortality, it was lower than in shock due to AMI in patients with obstructive coronary disease.