Cardiac MRI accurate for suspected cardiac tumor, predictive of long-term outcomes
Cardiac MRI demonstrated high diagnostic accuracy in patients with suspected cardiac tumor and may serve as a good independent predictor of long-term survival, researchers reported.
“Expert consensus documents recommend cardiovascular magnetic resonance (CMR) imaging as a key diagnostic tool in the evaluation of patients with suspected cardiac tumors,” Chetan Shenoy, MD, MBBS, MS, NIH-funded physician investigator, associate professor and director of the advanced cardiovascular imaging fellowship at the University of Minnesota Medical Center, and colleagues wrote. “There is a paucity of studies of patients with suspected cardiac tumor that correlate the imaging diagnosis with outcomes. For example, although CMR is widely used to exclude a cardiac mass, there are no studies with systematic follow-up of patients in whom a cardiac mass has been excluded to determine their long-term outcomes, including whether a cardiac mass is subsequently diagnosed during follow-up. Hence, the aim of this multicenter study was to determine the prognostic value of the ‘real-world’ CMR diagnosis in patients clinically referred to CMR for suspected cardiac tumor.”
Accuracy of cardiac MRI
For the analysis published in the European Heart Journal, researchers included 903 patients undergoing clinical cardiac MRI for suspected cardiac tumor (median age, 60 years; 46% men). A final diagnosis of either no mass, pseudomass, thrombus, benign tumor or malignant tumor was made after follow-up by experienced cardiac MRI physicians with Society for Cardiovascular Magnetic Resonance level III training. The primary endpoint was all-cause mortality.
The cardiac MRI diagnosis of no mass was made for 25% of the cohort, pseudomass for 16%, thrombus for 16%, benign tumor for 17% and malignant tumor for 23%.
During a median follow-up of 4.9 years, 376 patients died.
The cardiac MRI diagnosis was accurate in 98.4% of patients compared with the final diagnosis.
According to the study, the estimated 5-year rate of all-cause mortality was 22% for patients with no mass, 26% for pseudomass, 17% for benign tumor, 36% for thrombus and 73% for malignant tumor.
Researchers reported that patients with cardiac MRI diagnoses of pseudomass and benign tumor had similar survival compared with patients with no mass; however, those with thrombus and malignant tumor experienced greater all-cause mortality.
Influence of other clinical risk factors
Researchers determined that the following were each independently associated with all-cause mortality in this cohort:
- age (HR per 5-year increase = 1.09; 95% CI, 1.04-1.13);
- smoking (HR = 1.37; 95% CI, 1.11-1.69);
- left ventricular ejection fraction (HR per 5% decrease = 1.05; 95% CI, 1.01-1.1);
- extracardiac malignancy (HR = 2.32; 95% CI, 1.81-2.97);
- cardiac MRI diagnosis of thrombus (HR relative to diagnosis of no mass = 1.46; 95% CI, 1-2.11); and
- cardiac MRI diagnosis of malignant tumor (HR relative to diagnosis of no mass = 3.31; 95% CI, 2.4-4.57).
According to the study, the addition of the cardiac MRI diagnosis to a clinical model lacking the cardiac MRI increased the X2 statistic from 215.8 to 299.8 (P < .001), indicating that cardiac MRI diagnosis had incremental value for patients with and without an extracardiac malignancy.
“The present study is the largest imaging study to date for the diagnosis of cardiac tumor and confirms the high accuracy of CMR previously reported in smaller cohorts in whom cardiac tumors were known to be present,” the researchers wrote. “More importantly, we found that CMR also has high accuracy in excluding a cardiac tumor. The significance of this finding is demonstrated by the observation that nearly half the CMRs (385/903) were requested to evaluate a suspected tumor in patients later found to have either no mass or pseudomass.”