A retrospective analysis was carried out on consecutive stress myocardial perfusion procedures carried out during the period 2016 – 17. NTG rest scans for myocardial viability assessment are not part of this study. Out of the total of 456 procedures , 171 post PCI / CABG patients were excluded from this study and remaining 285 were analysed. The study group included 75 females (26%); Age Range 26 to 83 years. Group I patients (103; 36%) were being investigated first time for the presence of CAD, Group II (86 patients, 30%) were being evaluated for borderline stenosis after recent CAG. Group III (32 patients,11%) were found to have significant CAD in CAG including occlusions and required ischemia assessment and Group IV (64 patients, 23%) had undergone CAG or MPI in the past and were being treated as mild CAD and being re-investigated now.
The stress protocol was treadmill exercise in 187 (66 %) and pharmacological in 98 (34%; supine adenosine 62, erect bicycle adenosine 35 and dobutamine in only one). Among the entire study group of 285 patients, scan detected inducible ischemia in 44 patients (15 %) ,Normal in 227, Non-ishemic cardiomyopathy in 11 and only old infarct in 3. Scan detected CAD in 2 out of 18 asymptomatic patients (1 out of 12 with positive TMT and 1 out of 6 with negative TMT reports). Among patients undergoing cardiac risk assessment for non-cardiac surgery (n=29; liver transplant 17 and others 12) significant LAD disease was detected in one. Among patients with LBBB (n=13), scan was normal in 10 and cardiomyopathy was found in 3.
Appropriateness for the scan indication was assessed based on standard criteria in the literature. For the entire study group (n=285), the procedure was appropriate in 90%, uncertain in 7 % and inappropriate in 3 %. In patients with borderline stenosis (Gr II) ischemia was detected only in 16 % . In patients with significanticant CAD (Gr III) stress MPI confirmed ischemia in some territories in 62 % .
The results of our study are given in the table below.
Our study indicates that stress MPI is being used appropriately in our practice.