The thesis aimed to investigate cystatin C and creatinine-based estimates of glomerular filtration rate (eGFR), both at admission and during follow-up, on the combined endpoint of cardiovascular death and myocardial infarction in patients with acute coronary syndrome (ACS). We also evaluated two cystatin C assays and assessed genetic determinants of cystatin C concentrations. We used the PLATelet inhibition and Patient Outcomes study, where all types of ACS patients (n=18624) were randomized to ticagrelor or clopidogrel treatment. Multivariable Cox regression models, including clinical variables and biomarkers (troponin and NT-proBNP), and c-statistics were calculated. Cystatin C and the creatinine-based CKD-EPI equation exhibited similar significant prognostic impact on the combined endpoint, with Area Under Curves (AUC) 0.6923 and 0.6941, respectively. Follow-up samples of renal biomarkers did not improve risk prediction. Patients randomized to ticagrelor treatment were associated with a non-sustained larger increase in renal markers at discharge, but neither the change nor the difference between the randomized groups affected cardiovascular risk. Two different cystatin C assays exhibited good correlation 0.86 (95% confidence interval 0.85-0.86), however moderate level of agreement. Risk prediction with a combination of creatinine and cystatin C did not outperform the creatinine-based CKD-EPI equation, AUC: 0.6913 and 0.6924, respectively (n=13050). The genetic polymorphism rs6048952 independently affected the cystatin C concentration with mean levels of 0.85mg/L, 0.80mg/L and 0.73mg/L for the A/A, A/G, and G/G genotypes, respectively. The genetic polymorphism did not affect outcome overall, however in the non-ST-elevation ACS subgroup a signal that genetic polymorphism may be associated with cardiovascular death was observed (p=0.002). In conclusion: cystatin C or eGFR, irrespective of equation or assay, are important cardiovascular risk factors in ACS patients. Nonetheless, the incremental value of adding any renal variable, to a multivariable risk model, is small. Further research on the impact of cystatin C genetic polymorphism is warranted. / <p>PhD, i medicin.</p>
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:uu-197852 |
| Date | January 2013 |
| Creators | Åkerblom, Axel |
| Publisher | Uppsala universitet, Kardiologi, Uppsala |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, info:eu-repo/semantics/doctoralThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, 1651-6206 ; 891 |
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