Prognostic Significance of Delayed-Enhancement Magnetic Resonance Imaging. Survival of 857 Patients With and Without Left Ventricular Dysfunction

OBJECTIVES:  Left ventricular ejection fraction is a powerful independent predictor of survival in cardiac patients, especially those with coronary artery disease. Delayed-enhancement magnetic resonance imaging (DE-MRI) can accurately identify irreversible myocardial injury with high spatial and contrast resolution. To date, relatively limited data are available on the prognostic value of DE-MRI, so we sought to determine whether DE-MRI findings independently predict survival.

METHODS:  The medical records of 857 consecutive patients who had complete cine and DE-MRI evaluation at a tertiary care center were reviewed regardless of whether the patients had coronary artery disease. The presence and extent of myocardial scar were evaluated qualitatively by a single experienced observer. The primary, composite end point was all-cause mortality or cardiac transplantation. Survival data were obtained from the Social Security Death Index.

RESULTS:  The median follow-up was 4.4 years; 252 patients (29%) reached one of the end points. Independent predictors of mortality or transplantation included congestive heart failure, ejection fraction, and age (P<0.0001 for each), as well as scar index (hazard ratio, 1.26; 95% confidence interval, 1.02 to 1.55; P=0.033). Similarly, in subsets of patients with or without coronary artery disease, scar index also independently predicted mortality or transplantation (hazard ratio, 1.33; 95% confidence interval, 1.05 to 1.68; P=0.018; and hazard ratio, 5.65; 95% confidence interval, 1.74 to 18.3; P=0.004, respectively). Cox regression analysis showed worse outcome in patients with any DE in addition to depressed left ventricular ejection fraction (<50%).

CONCLUSION:  The degree of DE detected by DE-MRI appears to strongly predict all-cause mortality or cardiac transplantation after adjustment for traditional, well-known prognosticators. 

PMID: 19901193

Posted in Magnetic Resonance Imaging and tagged , , , , , .

One Comment

  1. Very interesting data! It encompasses a large group of patients with follow-up, for up to 4.4 years (median follow-up).

    Some of the most interesting findings (in my opinion) are:

    – The majority of patients without documented CAD had no DE (but not all of them); In contrast, 79% of patients with CAD had some DE. It would be interesting to know the risk factors of those patients with DE but no documented CAD (it has been shown that up to 20% of diabetics may present with occult subendocardial infarcts identified by MRI).

    – The Scar Index used by the authors independently predicted death/transplantation in the multivariable model; as well as in the CAD group.

    – This is probably one of the most interesting/intriguing findings: “In patients with LVEF >50%, the presence of DE predicted a worse outcome than the absence of DE. A similar pattern was observed in patients with LVEF <50%. Patients with LVEF <50% and with DE had the worst outcome. Importantly, patients with LVEF >50% and DE had survival characteristics similar to those patients with LVEF <50% and no DE." --- So, is this further proof that we can use DE as a surrogate for diastolic dysfunction? Is the presence and degree of scar (fibrosis) directly related to myocardial stiffness and therefore a marker of diastolic dysfunction (related ) that may explain the difference in prognosis in patients with similar EF?

    – “Even small amounts of DE-MRI-identified scar denoted substantially higher cardiac risk.”

    – “The risk of death/transplantation increased progressively as the extent of DE increased.”

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