Cardiovascular

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

Sundermeyer J, Li S, et al. • Journal of the American Heart Association • 2026

PubMed 42622204 DOI 10.1161/JAHA.125.047854

TL;DR

In acute myocardial infarction-related cardiogenic shock, lower arterial pulsatility index (API) and modified API (mAPI) were associated with increased in-hospital mortality, suggesting these measures may facilitate early risk assessment and guide tailored treatment decisions.

Key Findings

Results

Median API and mAPI values in AMI-CS patients were 2.1 and 1.7, respectively.

Among 487 patients with AMI-CS, median API was 2.1 (IQR, 1.3–3.2; n=139) and median mAPI was 1.7 (IQR, 1.0–2.8; n=487)
API was calculated as systemic arterial pulse pressure divided by pulmonary capillary wedge pressure
mAPI used pulmonary artery diastolic pressure instead of wedge pressure
Data were drawn from the multicenter CSWG (Cardiogenic Shock Working Group) registry

Results

API and mAPI were strongly correlated with each other.

Pearson r=0.75, P<0.001 between API and mAPI
mAPI was available for all 487 patients, while API was available for a subset of 139 patients
mAPI using pulmonary artery diastolic pressure was developed as a practical alternative when wedge pressure is unavailable

Results

Lower API was associated with significantly higher in-hospital mortality.

In-hospital mortality was 47.1% in low API patients versus 24.6% in higher API patients
Odds ratio for in-hospital mortality with low API: OR 2.728 (95% CI, 1.341–5.705); P=0.006
Every 0.5-unit decrease in API was associated with a 2.4% increase in in-hospital mortality (β=0.024 [95% CI, 0.002–0.045]; P=0.030)

Results

Lower mAPI was also independently associated with higher in-hospital mortality.

In-hospital mortality was 44.1% in low mAPI patients versus 32.2% in higher mAPI patients
Odds ratio for in-hospital mortality with low mAPI: OR 1.657 (95% CI, 1.147–2.402); P=0.007
Every 0.5-unit decrease in mAPI was associated with a 1.4% increase in in-hospital mortality (β=0.014 [95% CI, 0.002–0.026]; P=0.022)

Results

Native heart survival was lower in patients with low API or mAPI.

Native heart survival was 41.4% versus 59.4% in low versus higher API groups (P=0.051)
Native heart survival was 41.2% versus 59.1% in low versus higher mAPI groups (P<0.001)
Native heart survival accounts for survival without the need for mechanical circulatory support or transplant as a bridge

Results

Lower API and mAPI correlated with reduced left ventricular ejection fraction (LVEF).

Both API and mAPI showed significant correlation with LVEF in AMI-CS patients
This finding supports API and mAPI as hemodynamic surrogates of left ventricular function
Logistic and linear regression, spline modeling, and ROC curve analysis were used to assess these associations

Methods

The study used logistic/linear regression, spline modeling, and receiver operating characteristic curve analysis to assess associations.

The study population comprised 487 patients with AMI-CS from the multicenter CSWG registry
API was available in 139 patients; mAPI was available in all 487 patients
Analytical methods included logistic and linear regression, spline modeling, and ROC curve analysis
The study assessed associations with both clinical characteristics and in-hospital outcomes

What This Means

This research suggests that a measurement called the arterial pulsatility index (API) — derived from standard heart catheterization data — can help predict outcomes in patients experiencing cardiogenic shock following a heart attack (AMI-CS). API is calculated by dividing the difference between the highest and lowest blood pressure readings (pulse pressure) by the pressure in the lungs' blood vessels. A modified version (mAPI) uses a slightly different lung pressure measurement that is more commonly available. In a registry of 487 patients across multiple hospitals, patients with lower API or mAPI values had significantly higher rates of in-hospital death — nearly double the mortality rate compared to patients with higher values — and were less likely to survive using their own heart. The study found that each 0.5-unit drop in API was associated with roughly a 2.4% increase in the chance of dying in the hospital, and each 0.5-unit drop in mAPI was associated with a 1.4% increase. Lower API and mAPI values also corresponded with weaker heart pump function as measured by ejection fraction. Because mAPI can be calculated from measurements that are routinely collected in critically ill heart patients, it may be more practically useful than the standard API in real-world clinical settings. This research suggests that API and mAPI could serve as early warning tools to identify the sickest cardiogenic shock patients and potentially guide decisions about treatment intensity, including the use of mechanical heart support devices. The findings add to a growing body of evidence that simple hemodynamic calculations derived from standard monitoring equipment can provide meaningful prognostic information beyond traditional markers in this high-risk patient population.

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Citation

Sundermeyer J, Li S, Ton V, Kataria R, Zweck E, Garan A, et al.. (2026). Arterial Pulsatility Index in Acute Myocardial Infarction-Related Cardiogenic Shock: Clinical Characteristics and Association With Outcomes.. Journal of the American Heart Association. https://doi.org/10.1161/JAHA.125.047854

Key Findings

What This Means

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