Left ventricular contractile reserve as a determinant of adverse clinical outcomes: a systematic review

Area of Science:

• Cardiology
• Diagnostic Imaging
• Clinical Outcomes Research

Background:

• Abnormal left ventricular contractile reserve is frequently observed in stress echocardiography.
• This finding may suggest underlying obstructive coronary artery disease.
• The prognostic implications and assessment methods for this response, without known causes, are not well-established.

Purpose of the Study:

• To systematically review and characterize abnormal left ventricular contractile response.
• To evaluate the clinical outcomes and prognostic value of this response.
• To identify commonly used techniques and indices for assessing left ventricular contractile reserve.

Main Methods:

• Systematic review of 27 eligible studies.
• Analysis of various indices for measuring left ventricular contractile reserve, with a focus on Δleft ventricular ejection fraction.
• Review of different stress modalities, predominantly dobutamine stress echocardiogram, followed by exercise stress echocardiogram.

Main Results:

• Left ventricular contractile reserve was assessed using diverse indices, most commonly Δleft ventricular ejection fraction.
• Dobutamine stress echocardiogram was the most frequent imaging modality employed.
• All but one study showed a significant link between absent left ventricular contractile reserve and higher rates of cardiovascular events, cardiac death, and all-cause mortality.

Conclusions:

• Abnormal left ventricular contractile reserve is a significant indicator of poor prognosis.
• The absence of contractile reserve is associated with increased cardiovascular morbidity and mortality.
• Further research into standardized assessment and clinical application is warranted.