Diagnostic Tools and Prevalence of Septic Cardiomyopathy in Sepsis and Septic Shock: A Prospective Pilot Study

Objective

Cardiovascular damage is a common complication of sepsis, with an incidence of 10% to 70%. Septic cardiomyopathy (SCM) occurs in ICUs as a reversible myocardial damage in sepsis patients. Despite various proposed diagnostic tools, none are specifically tailored for SCM. This study aims to evaluate different echocardiography-based diagnostic tools and determine the SCM rate in our population.

Design and method

A single-centre, prospective observational study was conducted at a tertiary reference hospital from March to May 2024. Patients meeting Sepsis-3 criteria, aged over 18 years, and treated in the ICU were included. Ethical approval was obtained from the regional ethical committee. Transthoracic echocardiogram (TTE) and hemodynamic measurements were performed within 48 hours of patient identification and repeated within 10 days. A diagnosis of septic cardiomyopathy (SCMP) was evaluated using three different diagnostic tools: left ventricular ejection fraction (LVEF <50% or >10% decrease from baseline), cardiac power output (CPO <0.6W), and afterload-related cardiac performance (ACP <80%) based on values reported in the literature. Demographic and descriptive data were extracted from electronic medical records.

Results and conclusions

Results: Thirty-eight patients (mean age 61±13 years; 63.2% males) were enrolled. The median SOFA score was 9.5 [IQR, 8-11], APACHE II score 19 [16-22], and SAPS II 42 [32-51]. Median lactate levels were 3.1 [2.1-4.9] mmol/L, WBC count 16 [12-21] x10^9/L, PCT 11.2 [3.5–31.7] ng/mL, CRP 300 [179-407] mg/L, and troponin I 214 [47-627] ng/L. The median time between TTEs was 6 [4-9] days.

In patients diagnosed with SCMP based on LVEF, seven (19.4%) had SCMP, showing significantly lower velocity time integral (VTI: 13.2±3.3 vs 18.1±4.7 cm, p=0.013) and stroke volume (SV: 50.4±13.8 vs 67.7±18.5 ml, p=0.026), and higher heart rate (HR: 106±14 vs 87±20 bpm, p=0.028) compared to non-SCMP patients (n=31, 80.6%). For CPO-based diagnosis, six patients (20.7%) had SCMP, with significantly lower VTI (13.2±2.8 vs 17.9±4.9, p=0.029), SV (47.2±11.5 vs 67.5±18.5 ml, p=0.015), and cardiac output (CO: 3.9±0.5 vs 6.1±1.7 L/min, p<0.001), and a trend towards lower cardiac index (CI: 1.7±0.5 vs 2.6±0.8 L/min/m2, p=0.07) compared to twenty-nine non-SCMP patients. The prevalence of SCMP based on ACP was higher than in the LVEF or CPO group, with eighteen patients (51.4%) diagnosed with SCMP. Seventeen patients had slightly restricted cardiac function (ACP 60-80%) and one had moderately restricted cardiac function (ACP 40-60%). Comparatively, ACP-based SCMP patients had significantly lower mean arterial pressure (MAP: 98±17 vs 109±12 mmHg, p=0.025), CI (2.2±0.7 vs 2.8±0.8 l/min/m2, p=0.011), CO (4.6 [4.0-5.5] vs 6.4 [5.5-7.1] L/min, p=0.005), and SV (55 [43-66] vs 70 [59-82] ml, p=0.013), but higher central venous pressure (CVP: 15±6 vs 11±6 mmHg, p=0.032) than the seventeen non-SCMP patients. No significant differences were observed in lactate levels, VIS score, and survival rates between SCMP and non-SCMP groups.

Conclusions

Based on the three diagnostic tools, the prevalence of SCM in our study group varied from 19.4% to 51.4% and did not differ from the rates reported in the literature. Further analysis is necessary to determine the best diagnostic tool for SCM, requiring a larger sample group.