Arterial Pulsatility Index in Acute Myocardial Infarction-Related Cardiogenic Shock: Clinical Characteristics and...

The arterial pulsatility index (API) is a promising hemodynamic surrogate of left ventricular function, but its prognostic value in acute myocardial infarction-related cardiogenic shock (AMI-CS) remains unclear. This study evaluated associations between API, a modified API (mAPI), clinical characteristics, and in-hospital outcomes in AMI-CS.

Patients with AMI-CS in the multicenter CSWG (Cardiogenic Shock Working Group) registry with available API or mAPI were analyzed. API was calculated as systemic arterial pulse pressure/pulmonary capillary wedge pressure; mAPI used pulmonary artery diastolic pressure instead of wedge pressure. Logistic/linear regression, spline modeling, and receiver operating characteristic curve analysis were used to assess associations with clinical characteristics and in-hospital outcomes.

Among 487 patients with AMI-CS, median API and mAPI were 2.1 (interquartile range [IQR], 1.3-3.2; n=139) and 1.7 (IQR, 1.0-2.8; n=487), respectively. API strongly correlated with mAPI (Pearson r=0.75, P<0.001). Native heart survival was lower in patients with low API (41.4% versus 59.4%, P=0.051) or mAPI (41.2% versus 59.1%, P<0.001). Lower API or mAPI correlated with reduced left ventricular ejection fraction and was associated with higher in-hospital mortality (47.1% versus 24.6%; odds ratio [OR], 2.728 [95% CI, 1.341-5.705]; P=0.006; and 44.1% versus 32.2%; OR, 1.657 [95% CI, 1.147-2.402]; P=0.007). Every 0.5-unit decrease in API or mAPI was associated with a 2.4% (β=0.024 [95% CI, 0.002-0.045]; P=0.030) and 1.4% (β=0.014 [95% CI, 0.002-0.026]; P=0.022) increase in in-hospital mortality.

In AMI-CS, lower API and mAPI were associated with increased mortality. API and mAPI may facilitate early risk assessment and guide tailored treatment decisions in AMI-CS.