Impact of long-axis function on cardiac surgical outcomes in patients with radiation-associated heart disease.
BACKGROUND
Malignancy-associated thoracic radiation leads to radiation-associated cardiac disease (RACD) that often necessitates cardiac surgery. Myocardial dysfunction is common in patients with RACD. We sought to determine the predictive value of global left ventricular ejection fraction and long-axis function left ventricular global longitudinal strain (LV-GLS) in such patients.


METHODS
We studied 163 patients (age, 63 ± 14 years; 74% women) who had RACD and underwent cardiac surgery (20% had reoperations) between 2000 and 2003. In addition to standard echocardiography, LV-GLS (%) was derived from the average of 18 segments in 3 apical views of the left ventricle, using velocity vector imaging. Standard clinical and demographic parameters were recorded. All-cause mortality was recorded.


RESULTS
The mean duration between cardiac surgery and the last chest radiation was 18 ± 12 years. The median European System for Cardiac Operative Risk Evaluation (EuroSCORE) was 8, and 88 patients died over 6.6 ± 4 years. A total of 52% of patients had ≥ II+ mitral regurgitation; 23% of patients had severe aortic stenosis; and 39% of patients had ≥ II+ tricuspid regurgitation. The mean left ventricular ejection fraction was 54% ± 13%, and the mean LV-GLS was -12.9% ± 4%. In a Cox proportional survival analysis, lower LV-GLS was predictive of mortality in univariable analysis (hazard ratio, 1.07 (95% confidence interval, 1.01-1.14); P = .006); however, after adjustment for other variables, the association became nonsignificant. In patients with a EuroSCORE <median, abnormal LV-GLS (<-14.5%) was associated with significantly higher mortality (48%), compared with those with normal LV-GLS (32%).


CONCLUSIONS
In patients who have RACD and undergo cardiac surgery, LV-GLS does not sufficiently discriminate and is not independently predictive of long-term outcomes. However, in patients with a low EuroSCORE, abnormal LV-GLS was associated with higher mortality, compared with those with normal LV-GLS.
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Srisakul
S
Chirakarnjanakorn
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Zoran B
ZB
Popović
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Willis
W
Wu
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Ahmad
A
Masri
Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Nicholas G
NG
Smedira
Department of Cardiothoracic Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Bruce W
BW
Lytle
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio.
Brian P
BP
Griffin
Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio. Electronic address: desaim2@ccf.org.
Milind Y
MY
Desai
D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality; D016009:Chi-Square Distribution; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D016017:Odds Ratio; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011832:Radiation Injuries / Q000175:diagnosis / Q000209:etiology / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D011878:Radiotherapy / Q000009:adverse effects; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013314:Stress, Mechanical; D013318:Stroke Volume; D013899:Thoracic Neoplasms / Q000401:mortality / Q000532:radiotherapy*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
echocardiography; outcomes; radiation-associated cardiac disease; strain