The Relationship of Carotid Plaque, Intima Media Thickness (IMT), Resistivity Index (RI) and Pulsatility Index(PI) in Asian-Indian Patients with Acute Ischemic Stroke with and without Type2 DM

Aim: To determine the relationship of carotid plaque, intima media thickness (IMT), resistivity index (RI) and pulsatility index (PI) and prevalence of different risk factors with acute ischemic stroke and stroke subtypes in both diabetic and non-diabetic subjects. Materials and methods: 80 cases of acute ischemic strokes and 40 healthy controls were included in the study. The plaque, IMT, RI and PI were measured by carotid duplex ultrasound. Results: 31 subjects were Type 2 diabetic, 54 hypertensive while 25 were both diabetic and hypertensive. 23 cases (28.75%) had lacunar stroke (LACI), 32 (40%) stroke involving partial anterior circulation(PACI), 10(12.5%) stroke in posterior circulation (PACI) and 15(18.75%) stroke involving total anterior circulation(TACI) respectively. The mean IMT (0.88 ± 0.19mm), RI(0.76 ± 0.05) and PI(1.71 ± 0.19) of patients and mean IMT (0.6±0.09mm), RI (0.61 ± 0.06) and PI (1.53 ± 0.11) of controls were statistically significant (p-0.000). The mean values of IMT, PI and RI were significantly higher in diabetics (IMT-0.90 ± 0.16 VS 0.64 ± 0.11, p-0.013; PI-1.76 ± 0.20 VS 1.49 ± 0.09, P-0.000 and RI-0.76 ± 0.04 VS 0.59 ± 0.06, P-0.000) and similarly the mean values for IMT, PI and RI in hypertensives as compared to controls (IMT-0.88 ± 0.16 vs 0.65 ± 0.10, P-0.006; PI1.69 ± 0.18 vs 1.49 ± 0.09, P-0.000 and RI 0.76 ± 0.04 vs 0.59 ± 0.06, P-0.000). The mean IMT, PI and RI were increased significantly in smokers compared to controls (IMT-0.93 ± 0.20 vs 0.63 ± 0.06, P-0.000; PI-1.82 ± 0.22 vs 1.49 ± 0.09, P-0.000 and RI-0.77 ± 0.04 vs 0.59 ± 0.06, P-0.000). Type 3 plaque accounted for 27 (56.2%) cases and Type 2 plaque 12 (25%) cases. The total number of plaques in patients as compared to controls were significantly more (P-0.0034) and the mean plaque area was 46 mm2 for cases and 20 mm2 for control (P-0.0001). TACI was the most common type of ischemic stroke seen in DM (60%), HTN (66.6%) and smokers (66.7%). Plaques (73.3%), IMT (0.90 ± 0.12), PI(1.72 ± 0.14) and RI (0.76 ± 0.13) were more commonly associated with TACI subtype. On multivariate analysis using ANOVA, the mean PI was highly significant (0.000) in relation to types of plaque. Summary and Conclusions: IMT, RI, PI and plaque type are useful diagnostic parameters for acute ischemic stroke and its subtypes. They can be used as noninvasive tools for predicting and preventing ischemic stroke in smokers as well as subjects with DM and hypertension.