Predictor Naïve Temporal Baseline Hazard of Recurrent Ischemic Stroke

Abstract There are established correlation between risk factors and the recurrence of ischemic stroke (IS), however does the hazard of recurrent IS change although without the influence of established risk factors? This study aimed to quantify the hazard of recurrent IS at different time points after the index IS. This was a population cohort study extracted data of 7697 patients with a history of first IS attack registered with National Neurology Registry of Malaysia. A repeated time to recurrent IS model was developed using NONMEM version 7.5. Three baseline hazard models were fitted into the data. The best model was selected using maximum likelihood estimation, clinical plausibility and visual predictive checks. Three hundred and thirty-three (4.32%) patients developed at least one recurrent IS within the maximum 7.37 years follow-up. In the absence of significant risk factors, the hazard of recurrent IS was predicted to be 0.71 within the first month after the index IS and reduced to 0.022 between the first to third months after the index attack. The hazard of IS recurrence accelerated with the presence of typical risk factors such as hyperlipidaemia (HR, 2.64 [2.10-3.33]), hypertension (HR, 1.97 [1.43-2.72], and ischemic heart disease (HR, 2.21 [1.69-2.87]). In conclusion, the absence of significant risk factors, predicted hazard of recurrent IS was prominent in the first month after the index IS and was non-zero even three months after the index IS or later. Optimal secondary preventive treatment should incorporate the ‘nature risk’ IS recurrence.