Coronary artery calcification, cardiovascular events, and death: a prospective cohort study of incident patients on hemodialysis.
BACKGROUND
Coronary calcification in patients with end-stage renal disease (ESRD) is associated with an increased risk of cardiovascular outcomes and death from all causes. Previous evidence has been limited by short follow-up periods and inclusion of a heterogeneous cluster of events in the primary analyses.


OBJECTIVE
To describe coronary calcification in patients incident to ESRD, and to identify whether calcification predicts vascular events or death.


METHODS
Prospective substudy of an inception cohort.


METHODS
Tertiary care haemodialysis centre in Ontario (St Joseph's Healthcare Hamilton).


METHODS
Patients starting haemodialysis who were new to ESRD.


METHODS
At baseline, clinical characterization and spiral computed tomography (CT) to score coronary calcification by the Agatston-Janowitz 130 scoring method. A primary outcome composite of adjudicated stroke, myocardial infarction, or death.


METHODS
We followed patients prospectively to identify the relationship between cardiac calcification and subsequent stroke, myocardial infarction, or death, using Cox regression.


RESULTS
We recruited 248 patients in 3 centres to our main study, which required only biochemical markers. Of these 164 were at St Joseph's healthcare, and eligible to participate in the substudy; of these, 51 completed CT scanning (31 %). Median follow up was 26 months (Q1, Q3: 14, 34). The primary outcome occurred in 16 patients; 11 in the group above the median and 5 in the group below (p = 0.086). There were 26 primary outcomes in 16 patients; 20 (77 %) events in the group above the coronary calcification median and 6 (23 %) in the group below (p = 0.006). There were 10 deaths; 8 in the group above the median compared with 2 in the group below (p = 0.04). The hazard ratios for coronary calcification above, compared with below the median, for the primary outcome composite were 2.5 (95 % CI 0.87, 7.3; p = 0.09) and 1.7 (95 % CI 0.55, 5.4; p = 0.4), unadjusted and adjusted for age, respectively. For death, the hazard ratios were 4.6 (95 % CI 0.98, 21.96; p = 0.054) and 2.4 (95 % CI 0.45, 12.97; p = 0.3) respectively.


CONCLUSIONS
We were limited by a small sample size and a small number of events.


CONCLUSIONS
Respondent burden is high for additional testing around the initiation of dialysis. High coronary calcification in patients new to ESRD has a tendency to predict cardiovascular outcomes and death, though effects are attenuated when adjusted for age.
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Trevor J
TJ
Wilkieson
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada.
M Omair
MO
Rahman
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada ; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada.
Azim S
AS
Gangji
Department of Radiology, McMaster University, Hamilton, Canada.
Maurice
M
Voss
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Alistair J
AJ
Ingram
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Nischal
N
Ranganath
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada ; Faculty of Health Sciences, Simon Fraser University and Arthritis Research Centre of Canada, Richmond, Canada.
Charlie H
CH
Goldsmith
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Cathy Z
CZ
Kotsamanes
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Mark A
MA
Crowther
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada.
Christian G
CG
Rabbat
Department of Medicine, McMaster University, 50 Charlton Avenue East, Hamilton, L8N4A6 ON Canada ; Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Canada.
Catherine M
CM
Clase
Cardiovascular outcome; Coronary artery calcification; Death; End stage renal disease; Hemodialysis; Myocardial infarction