Negative stress echo: further prognostic stratification with assessment of pressure-volume relation

Area of Science:

• Cardiology
• Echocardiography
• Cardiovascular Physiology

Background:

• Maximal negative stress echocardiography (SE) identifies a subset of patients at low risk for future cardiac events.
• Standard SE assessment of regional wall motion misses crucial information on global left ventricular contractile reserve.
• End-systolic pressure-volume relationship (PVR) evaluation can provide insights into global contractile reserve.

Purpose of the Study:

• To evaluate the prognostic significance of PVR in patients who have undergone a negative stress echocardiography.
• To determine if PVR offers additional risk stratification beyond standard stress echo criteria.

Main Methods:

• Ninety-nine patients with negative exercise stress echo results were enrolled.
• The end-systolic pressure/end-systolic volume index (SP/ESV) was calculated at rest and peak stress to construct the PVR.
• Patients were followed under medical therapy to track cardiac events.

Main Results:

• During a median follow-up of 21 months, 29 cardiac events occurred (deaths, heart failure hospitalizations, worsening NYHA class).
• A stress-induced change in the SP/ESV index below 1.5 mm Hg/ml/m² was the strongest independent predictor of events (RR=29, p=0.001).
• Event-free survival was significantly lower (34%) in patients with a SP/ESV index change <1.5 compared to those with a change >1.5 (97%).

Conclusions:

• Stress-induced variation in the SP/ESV index can effectively identify preserved global contractility in patients with negative stress echo.
• This PVR-derived metric provides powerful additional risk stratification beyond standard stress echocardiography.
• SP/ESV index change offers a simple yet potent tool for identifying high-risk individuals within a seemingly low-risk stress echo cohort.