Background: The goals of this meta-analysis were to determine survival rates in patients with heart failure (HF) assessed by ¹²³I-MIBG imaging results using recently published studies and to determine the prognostic value of ¹²³I-MIBG imaging.
Methods: We reviewed published cohort studies carried out in Japan that compared the prognosis of patients with their ¹²³I-MIBG activity quantified as late heart-to-mediastinum ratio (H/M) or washout rate by performing a PubMed search for articles in English up to December 2006. Studies were selected if they analyzed a clearly defined lethal outcome (cardiovascular death) using life tables to estimate the odds ratio at 24 months after enrollment.
Results: Of 158 articles related to cardiac ¹²³I-MIBG, seven referred to studies that met the inclusion criteria: 5 evaluated H/M via ¹²³I-MIBG in a total of 866 patients and 4 calculated washout rate in a total of 491 patients. A low H/M indicated a high risk of cardiac death: pooled odds ratio, 5.2; 95% confidence interval (CI) of 3.1-5.7. A high washout was also associated with lethal events with a pooled odds ratio of 2.8 (CI: 1.6-5.0). The association between washout and cardiac death was heterogeneous (Chi-square = 11.0, P < 0.02), whereas that between late H/M and fatal events was homogeneous (Chi-square = 2.3, P = no significance).
Conclusion: This meta-analysis of published studies of ¹²³I-MIBG studies conducted in Japan indicated that both a decreased cardiac ¹²³I-MIBG activity (H/M) and an increased washout rate are indicative of a poor prognosis in patients with chronic heart failure.