Progression of coronary artery calcification and cardiac events in patients with chronic renal disease not receiving dialysis

Abstract

We tested for the presence of coronary calcifications in patients with chronic renal disease not on dialysis and studied its progression in 181 consecutive non-dialyzed patients who were followed for a median of 745 days. Coronary calcifications (calcium score) were tallied in Agatston units by computed tomography, and the patients were stratified into two groups by their baseline calcium score (100 U or less and over 100 U). Survival was measured by baseline calcium score and its progression. Cardiac death and myocardial infarction occurred in 29 patients and were significantly more frequent in those patients with calcium scores over 100 U (hazard ratio of 4.11). With a calcium score of 100 U or less, the hazard ratio for cardiac events was 0.41 and 3.26 in patients with absent and accelerated progression, respectively. Thus, in non-dialyzed patients, the extent of coronary calcifications was associated to cardiac events, and progression was an independent predictive factor of cardiac events mainly in less calcified patients. Hence, assessment of coronary calcifications and progression might be useful for earlier management of risk factors and guiding decisions for prevention of cardiac events in this patient population.

Figure 1

Adjusted survival according to baseline coronary artery calcification (CAC) score. Multivariable-adjusted (age, diabetes, GFR, and hypertension) association between baseline CAC score ⩽100 AU (continuous line) and CAC score >100 AU (dashed line) and survival. Survival was significantly (P=0.0017) worse in presence of CAC score >100 AU. AU, Agatston unit (for scoring CAC); GFR, glomerular filtration rate.

Figure 2

Adjusted survival according to progression of baseline coronary artery calcification (CAC) score. Multivariable-adjusted (age, diabetes, GFR, and hypertension) association between progressions of baseline CAC score (absent: ⩽25th percentile, continuous line; moderate: 25th–75th percentiles, dashed line; and accelerated: >75th percentile, dotted line). Survival was significantly (P<0.0068) worse in patients with accelerated progression. In patients with absent or moderate progression, survival curves overlapped. P-value represents significance across all three groups. AU, Agatston unit (for scoring CAC); GFR, glomerular filtration rate.