‘Routine intravascular ultrasound evaluation and change in stenting strategy in primary percutaneous intervention (RIST PCI)’

Background Intravascular ultrasound (IVUS) provides better assessment of vessel size, lesion length and plaque characteristics. There is paucity of data regarding the impact of IVUS on stenting pattern during primary percutaneous intervention (PCI) for ST elevation myocardial infarction (STEMI).Methods We included patients with STEMI undergoing IVUS-guided primary PCI. Diagnostic angiograms were analysed by two different operators who were not part of procedure. They were asked to formulate a treatment plan which included choice of stent diameters, length and number of stents based on angiographic assessment alone. The data were then compared with actual metrics derived from IVUS evaluation.Results Sixty-two patients were included. Left anterior descending artery was involved in 38/62(61.3%) cases. Mean stent diameters assessed by angiogram were 2.94 ± 0.4 mm and 3.01 ± 0.32 mm by cardiologist 1 and 2, respectively. IVUS-derived mean stent diameter was 3.5 ± 0.65 mm (p < 0.001). Mean stent length was 42.29 ± 19.29 mm by IVUS evaluation; while angiographically assessed values were 33.53 ± 11.53 (cardiologist 1) and 35.24 ± 12.97 mm (cardiologist 2) with a mean difference of 8.76 mm and 7.05 mm respectively (p < 0.001). Mean number of stents by IVUS evaluation was 1.42 ± 0.56, while by angiographic evaluation were 1.11 ± 0.37 and 1.13 ± 0.34 respectively (p < 0.001).Conclusions There was significant difference between IVUS derived and angiographically assessed culprit vessel metrics in patients undergoing primary PCI. Clinical outcomes of this discrepancy need further studies.