Ramesh D. Dhekne

Prognostic Value of Myocardial Perfusion Imaging in Patients With High Exercise Tolerance

BACKGROUNDnAlthough high exercise tolerance is associated with an excellent prognosis, the significance of abnormal myocardial perfusion imaging (MPI) in patients with high exercise tolerance has not been established. This study retrospectively compares the utility of MPI and exercise ECG (EECG) in these patients.nnnMETHODS AND RESULTSnOf 388 consecutive patients who underwent exercise MPI and reached at least Bruce stage IV, 157 (40.5%) had abnormal results and 231 (59.5%) had normal results. Follow-up was performed at 18+/-2.7 months. Adverse events, including revascularization, myocardial infarction, and cardiac death, occurred in 40 patients. Nineteen patients had revascularization related to the MPI results or the patients condition at the time of MPI and were not included in further analysis. Seventeen patients (12.2%) with abnormal MPI and 4 (1.7%) with normal MPI had adverse cardiac events (P<0.001). Cox proportional-hazards regression analysis showed that MPI was an excellent predictor of cardiac events (global chi2=13.2; P<0.001; relative risk=8; 95% CI=3 to 23) but EECG had no predictive power (global chi2=0.05; P=0.8; relative risk=1; 95% CI=0.4 to 3.0). The addition of Dukes treadmill score risk categories did not improve the predictive power of EECG (global chi2=0.17). The predictive power of the combination of EECG (including Duke score categories) and MPI was no better than that of MPI alone (global chi2=13.5).nnnCONCLUSIONSnUnlike EECG, MPI is an excellent prognostic indicator for adverse cardiac events in patients with known or suspected CAD and high exercise tolerance.

Timing for repeated treatment of hyperthyroid disease with radioactive iodine after initial treatment failure

Purpose It has been reported that the effect of radioactive iodine (RAI) treatment is complete in 4 to 6 months. This retrospective study evaluated the appropriate time for repeated treatment of hyperthyroid disease with RAI after initial treatment failure. Methods Outcomes of 128 patients treated with RAI for hyperthyroid disease were reviewed retrospectively at 3 and 6 months. Results Eighty patients (group A) were treated successfully with a single dose of RAI. Twenty patients (group B) required a second treatment dose. Twenty-eight patients were lost to follow-up. All patients in group A were clinically improved to various degrees at 3 months and continued to improve at 6 months. All eight patients in group B who showed no improvement at 3 months remained the same at 6 months. The difference between the two groups was statistically significant. Conclusion Patients with hyperthyroid disease who are unimproved at 3 months can be retreated with RAI without further delay.

Splenic concentration of bone imaging agents in functional asplenia

Three cases of sickle cell disease associated with functional asplenia are described. The spleen was not visualized on routine Tc-99m-sulfur colloid scan. The bone scan performed with Tc-99m-phosphate compounds revealed abnormal splenic activity in all three cases. The previous case reports and the literature on this subject are reviewed.

False negative Tc-99m hepatobiliary scan in a patient with Osler-Weber- Rendu disease

A 51-year-old woman with Osler-Weber-Rendu disease presented with right upper quadrant pain. Ultrasonography of the gallbladder and Tc-99m cholescintigraphy showed no evidence of acute cholecystitis. CT of the abdomen 9 hours after the hepatobiliary scan was consistent with acute cholecystitis. A gangrenous gallbladder was surgically removed after identification and ligation of an anomalous accessory right hepatic duct inserting directly into the gallbladder. The pathologic examination confirmed the diagnosis of acute ischemic acalculous cholecystitis.