Cardiovascular disease and diabetes or renal insufficiency the risk of ischemic stroke and risk factor intervention

University dissertation from Umeå : Umeå Universitet

Abstract: BackgroundIn patients with diabetes mellitus (DM) or chronic kidney disease (CKD), established cardiovascular disease (CVD) is associated with an increased risk of recurrent events and poor outcome. Ischemic stroke after an acute myocardial infarction (AMI) is a devastating event that carries high risks of decreased patient independence and death. Among patients with DM or CKD, the risk of an ischemic stroke within a year following an AMI is not known. Improved risk factor control is required to reduce the likelihood of CVD recurrence. Guidelines recommend target lipid profile and blood pressure values; however, data show that these targets are often not met. Therefore, there remains an urgent need for improved cardiovascular secondary preventive follow- up.AimsThe aims of the present studies were to define trends in the incidence and predictors of ischemic stroke after an AMI in patients with DM or CKD. Furthermore to assess whether secondary preventive follow-up with nurse-based telephone follow-up including medication titration after CVD improves risk factor values in patients with DM or CKD and to investigate if this method performs better than usual care to implement a new treatment guideline in diabetic patients.MethodsTo assess the risk of post-AMI ischemic stroke, patient data were obtained from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA). In separate studies, we compared a total of 173 233 AMI patients with and without DM, and 118 434 AMI patients with and without CKD.Within the nurse-based age-independent intervention to limit evolution of disease (NAILED) trial, we investigated a nurse-based cardiovascular secondary preventive follow-up protocol. Patients with acute coronary syndrome, stroke, or transient ischemic attack were randomized to receive either nurse-based telephone follow-up (intervention) or usual care (control). Low-density lipoprotein (LDL-C) levels and blood pressure (BP) were measured at 1 month (baseline) and 12 months post- discharge. Intervention patients with above-target baseline values received medication titration to achieve treatment goals, while the measurements for control patients were forwarded to their general practitioners for assessment. We calculated the changes in LDL-C level and BP between baseline and 12 months post-discharge, and compared these changes between 225 intervention patients and 215 control patients with concurrent DM or CKD. During the course of the NAILED trial, new secondary preventive guidelines for DM patients were released, including a new LDL-C target value. To assess adherence to the new guidelines within the NAILED trial, we compared LDL-C levels in the 101 intervention patients and 100 control patients with DM.ResultsIschemic stroke after AMIThe rates of ischemic stroke within one-year after admission for an AMI decreased over time, from 7.1% in 1998–2000 to 4.7% in 2007–2008 among DM patients, and from 4.2% to 3.7% during the same time periods for non-diabetic patients. Lower stroke risk was associated with percutaneous coronary intervention (PCI) and initiation of secondary preventive treatments in-hospital.In-hospital ischemic stroke occurred in 2.3% of CKD patients and 1.2% of non-CKD patients, with no change in these incidences over time. The rates of one-year post- discharge ischemic stroke decreased between 2003–2004 and 2009–2010 from 4.1% to 2.5% among CKD patients, and from 2.0% to 1.3% among non-CKD patients. Lower rates of post-discharge stroke were associated with PCI and statins.Cardiovascular secondary preventive follow-upAmong DM and CKD patients with above-target baseline values in the NAILED trial, the median LDL-C value at 12 months was 2.2 versus 3.0 mmol/L (p<0.001) and median systolic BP was 140 versus 145 mmHg (p=0.26) for intervention and control patients, respectively.Before the guideline change, 96% of the intervention and 70% of the control patients reached the target LDL-C value (p<0.001). After the guideline change, the corresponding respective proportions were 65% and 36% (p<0.001).ConclusionIschemic stroke is a fairly common post-AMI complication among patients with DM and CKD. This risk of stroke has decreased during recent years, possibly due to the increased use of evidence-based therapies. Compared with usual care, cardiovascular secondary prevention including nurse-based telephone follow-up improved LDL-C values at 12 months after discharge in patients with DM or CVD, and led to more efficient implementation of new secondary preventive guidelines.