Fractional shortening below 30% may be a useful echocardiographic parameter associated with clinically significant cardiac dysfunction in blunt TBI patients, capturing dysfunction missed by ejection fraction alone.
Key Findings
Results
A substantial proportion of blunt TBI patients who underwent early echocardiography had decreased fractional shortening, indicating possible cardiac dysfunction.
105 blunt TBI patients met inclusion criteria and underwent echocardiography within 48 hours of admission at a Level 1 Trauma Center during 2022-2023.
81 patients had normal fractional shortening (FS), 23 patients had decreased FS below 30%, and 1 had increased FS.
Patients with preexisting cardiac comorbidities were excluded to isolate TBI-related cardiac changes.
This was a retrospective cohort study at an American College of Surgeons verified Level 1 Trauma Center.
Results
Ejection fraction alone failed to detect cardiac dysfunction in the majority of patients with decreased fractional shortening.
19 of 23 (83%) patients with decreased FS below 30% had preserved ejection fraction on echocardiography.
All 81 patients with normal FS had preserved EF, confirming EF and FS tracked together only in the normal range.
Fractional shortening is described as 'a simple M-mode measure predictive of systolic function defined as the percentage change in left ventricular diameter between the end of diastole and systole.'
These findings suggest that relying solely on EF would miss the majority of FS-defined cardiac dysfunction in this population.
Results
Patients with decreased fractional shortening had worse clinical outcomes including increased ICU length of stay, inpatient mortality, and craniotomy/craniectomy rates.
Patients with decreased FS (below 30%) had increased ICU length of stay compared to those with normal FS.
Inpatient mortality was higher in patients with decreased FS.
Craniotomy/craniectomy rates were higher among patients with decreased FS.
These adverse in-hospital outcomes suggest FS below 30% is clinically significant, not merely an incidental echocardiographic finding.
Results
Subarachnoid hemorrhage was the most frequent intracranial abnormality found in patients with decreased fractional shortening.
The study assessed the association between echocardiographic signatures and specific intracranial abnormalities.
Subarachnoid hemorrhage was identified as the most common intracranial finding among the 23 patients with decreased FS.
The study evaluated echo reports for cardiac dysfunction as measured by EF, RWMAs, and FS in relation to intracranial pathology.
This association is consistent with known neurogenic cardiac effects of subarachnoid hemorrhage documented in prior literature.
Conclusions
Fractional shortening below 30% is proposed as a useful echocardiographic parameter to identify clinically significant cardiac dysfunction in blunt TBI patients.
Cardiac dysfunction following blunt TBI has been 'commonly defined as new decreased ejection fraction or new regional wall motion abnormalities,' but this study assessed FS as an additional parameter.
The authors conclude that 'FS below 30% may be a useful echocardiographic parameter associated with clinically significant cardiac dysfunction in blunt TBI patients.'
FS captured dysfunction in 83% of cases that would have been classified as normal by EF criteria alone.
The study suggests that standard definitions of TBI-related cardiac dysfunction may be insufficient without inclusion of FS.
What This Means
This research suggests that the heart can be significantly affected after a traumatic brain injury (TBI), and that the standard method doctors use to measure heart function—called ejection fraction (EF)—may miss most of these cases. The study looked at 105 adult patients hospitalized after blunt TBI who had heart ultrasounds (echocardiograms) done within 48 hours of arrival. Researchers found that 23 patients had a sign of reduced heart function called decreased 'fractional shortening' (FS), but 83% of those same patients had a normal ejection fraction. This means that if doctors only looked at EF, they would have missed the vast majority of patients with potential heart problems after brain injury.
Patients whose heart ultrasounds showed decreased fractional shortening had notably worse outcomes: they spent more time in the ICU, had higher rates of death during hospitalization, and were more likely to need emergency brain surgery (craniotomy or craniectomy). The most common type of brain bleed found in these patients was subarachnoid hemorrhage, a type of bleeding around the brain known to sometimes affect heart function through nerve pathways.
This research suggests that measuring fractional shortening—a simpler calculation than ejection fraction—could be a valuable additional tool for detecting heart dysfunction in TBI patients that would otherwise go unnoticed. Identifying these patients earlier may be important because their outcomes are significantly worse. Further prospective research would be needed to confirm whether routinely measuring FS and intervening early could improve patient outcomes.