Arterial Pulsatility Index in Acute Myocardial Infarction‐Related Cardiogenic Shock: Clinical Characteristics and Association With Outcomes

Background 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. Methods 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. Results 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. Conclusions 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.