Transient ischemic attack events and incident cardiovascular and non-cardiovascular complications: Observations from a large diversified multimorbid cohort.

Background: Transient ischemic attack (TIA) is a strong signal prompting the incidence of future cardiovascular and non-cardiovascular complications, in light of recent debate on the so-called "stroke-heart syndrome." We aimed to investigate the relation of TIAs to incident clinical events. Methods: Patients were drawn from three health plans with a wide spectrum of age groups and a wide mix of socio-economic/disability status. Two TIA cohorts in a retrospective design were used to achieve the study specific aims: (i) to investigate the incidence of TIA and associated cardiovascular and non-cardiovascular complications within 30 and 90 days from the onset of incident TIA events; and (ii) to examine the potential risk factors for developing incident TIA events in the general population with/without a history of prior stroke. Results: The incident TIA cohort consisted of 53,716 patients with an average age of 64.2 years (SD 15.2) and 46.1% male. Following TIA, the incidence proportions of ischemic stroke within 30 and 90 days were 2.7% and 3.8%, respectively, and for incident acute coronary syndrome being 0.94 and 1.84, respectively. Ventricular arrhythmia had proportions of 1.2 and 2.14, respectively within 30 and 90 days, with acute heart failure having values of 0.49 and 0.923. About 45% or more of the cardiovascular and non-cardiovascular complications occurred in the first 30 days following the incident TIA cases. About one-third of the recurrent TIA cases followed the incident TIA cases within a span of 30 days. Amongst comorbidities with stroke in the comorbid history, prior stroke provided the strongest risk factor in terms of odds ratio (OR = 8.34, 95% CI 7.21-9.66) for incident TIA events. Age was strongly associated with incident TIA events. Without a prior history of stroke (ischemic stroke/transient ischemic attack/thrombo-embolic events), valvular disease was the strongest risk factor from among the comorbidities (OR-1.87, 95% CI 1.51-2.32). Age also provided strong associations with incident TIA events. Conclusions: Following a TIA, there was a high risk of stroke, acute coronary syndrome, ventricular arrhythmia, acute heart failure, and non-cardiovascular complications.