Serum Creatinine Beneficial in Risk-Stratifying Patients With Pulmonary Embolism

Photo Credit: SyhinStas

Serum creatinine shows potential as a non-cardiac biomarker for assessing mortality risk among patients with pulmonary embolism.

“Current guidelines for the risk stratification of pulmonary embolism have limited defined roles for non-cardiac biomarkers,” Jose Gomez-Arroyo, MD, PhD, and colleagues wrote. “Serum creatinine is a ubiquitous but underused predictive biomarker for risk stratification.”

For a study presented at CHEST 2024, Dr. Gomez-Arroyo and colleagues aimed to determine the predictive role of serum creatinine among patients with acute pulmonary embolism (PE).

The study was a retrospective analysis of 479 pulmonary embolism cases between 2018 and 2022. The Pulmonary Embolism Response Team (PERT) at the authors’ healthcare facility stratified patients into low (43.6%), intermediate (31.7%), and high (26.4%) risk categories based on the European Society of Cardiology’s Guidelines.

PERT recorded the first measurement of each patient’s serum creatinine level in their chart and collected the initial values at index pulmonary embolism.

Serum Creatinine & 90-Day Mortality

The median creatinine level was 1.05 mg/dL (IQR 0.35). 79.5% of low-risk patients received heparin monotherapy, compared to 72.8% of intermediate-risk and 53.6% of high-risk patients. 3.4% of low-risk, 15.2% of intermediate risk, and 20.1% of high-risk patients had catheter-directed therapy. Percutaneous mechanical thrombectomy was performed on 11% of low-risk, 11.2% of intermediate-risk, and 12.9% of high-risk patients. Only 12% of high-risk patients received systemic thrombotic—none of the low or intermediate-risk patients received this treatment.

Median serum creatinine levels were 0.965 (IQR 0.545), 0.980 (IQR 0.44), and 1.16 (IQR 0.8) for low, intermediate, and high-risk patients, respectively. 30% of the patients met the criteria for acute kidney injury (AKI) following treatment. These patients had a median serum creatinine level of 1.51 mg/dL and GFR of 42 mL/min, resulting in chronic kidney disease of varying degrees:

• Stage 1: 119
• Stage 2: 137
• Stage 3A: 32
• Stage 3B: 19
• Stage 4: 13
• Stage 5: 6

As a result, the researchers found that patients with a serum creatinine level above 1.05 mg/dL had a significantly higher risk for death within 90 days of index pulmonary embolism. The authors performed a Multivariate Cox regression, which revealed that these patients faced a 13% increased risk for death per 1 unit change in Z-SCr (HR 1.136, 95%CI 1.023-1.262, p < 0.05) after adjusting for PE-risk.

Using Serum Creatinine in Risk Stratification

The results “support an association between serum creatinine at the time of the index PE and increased 90-day mortality,” according to Dr. Gomez-Arroyo and colleagues.

“Readily available and economical biomarkers such as serum creatinine have been associated with worse outcomes in different cardiovascular diseases,” they wrote. “We provide evidence to suggest that SCr could be a non-cardiac biomarker to help risk-stratify patients with PE.”