Adverse effect of increased left ventricular wall thickness on five year outcomes of patients with negative...

Area of Science:

• Cardiology
• Cardiovascular Imaging

Background:

• Assessing cardiac prognosis in patients without inducible ischemia but with increased left ventricular end-diastolic wall thickness (EDWT).
• Evaluating the prognostic significance of EDWT in the absence of dobutamine-induced left ventricular wall motion abnormalities (WMA).

Purpose of the Study:

• To determine if increased LV EDWT, without dobutamine-induced WMA, predicts cardiac events.
• To identify novel risk factors for adverse cardiac outcomes in specific patient populations.

Main Methods:

• 175 patients underwent dobutamine stress cardiovascular magnetic resonance (DCMR) with gradient-echo cines (1999-2001).
• Patients had preserved LV ejection fraction (>55%) and no inducible WMA.
• Cardiac events (death, MI, USA, CHF) were tracked for an average of 5.5 years post-DCMR.

Main Results:

• A LV EDWT ≥12 mm independently predicted increased cardiac death and myocardial infarction (MI) (HR 6.0, p=0.0016).
• Increased LV EDWT also predicted a composite endpoint of MI, cardiac death, and hospitalization for unstable angina (USA) or congestive heart failure (CHF) (HR 3.0, p=0.0005).
• Multivariate analysis adjusted for Framingham risk factors confirmed these associations.

Conclusions:

• Cardiovascular magnetic resonance (CMR) measures of increased LV wall thickness are a risk factor for cardiac events, even with negative dobutamine stress tests for ischemia.
• LV wall thickness should be considered in risk stratification for patients undergoing dobutamine stress imaging.
• Further research on LV wall thickness and mass using steady-state free precession techniques is recommended.