Rate of in-hospital cardiovascular complications in patients with postoperative renal dysfunction after surgical myocardial revascularization

Kremneva L.V.¹, Abaturova O.V.², Shalaev S.V.²

1) Scientific and Practical Medical Centre,
2) Tyumen State Medical University, Tyumen, Russia

The study was aimed at revealing the factors associated with renal dysfunction having developed after coronary artery bypass grafting (CABG) and assessing the in-hospital cardiovascular complications rate amongst patients with postoperative renal dysfunction.

The study included a total of 99 patients presenting with stable angina pectoris and having indications for CABG. The mean age of the patients amounted to 57±7 years, with the average duration of coronary artery disease (CAD) of 6±5.7 years. A multi-vessel lesion of coronary arteries was revealed in 69.7% of patients, ≥50% stenosis of the trunk of the left coronary artery was diagnosed in a further 15.1%. CABG was performed in conditions of assisted circulation (AC) in 88.9% of patients and on the functioning heart in 11.1%. We implanted from 1 to 4 grafts to each patient. At admission, and then on the first and second postoperative days after CABG we determined blood serum creatinine and calculated the creatinine clearance (CrCl) according to the Cockcroft-Gault equation. A decrease in the CrCl <60 ml/min was regarded as renal dysfunction. Assessing the cardiovascular complications rate we took into consideration cases of cardiac death, perioperative myocardial infarctions (POMI), severe acute cardiac insufficiency having required placement of a counterpulsator, and as well as the proportion of patients with paroxysmal atrial fibrillation. We also evaluated the frequency of repeat sternotomy.

The incidence rate of transitory renal dysfunction following CABG amounted to 18.2%. The factors associated with a decrease in the CrCl <60 ml/min after CABG were found to be as follows: age above – Me 62.5 (range 59–68) years, increased duration of AC above – Me 103 (range 88–133) min and prolonged time of aortic occlusion (AO) above – Me 53 (range 44–60) min, severe postoperative acute cardiac insufficiency, and re-sternotomy. The cumulative rate of in-hospital cardiovascular complications turned out to be significantly higher (55.6 versus 18.5%, p=0.001) amongst patients with postoperative renal dysfunction. We also revealed a substantially higher incidence rate of re-sternotomies in the cohort of patients with a CrCl <60 ml/min after CABG (11.1 vs. 1.2%, p=0.027).

Hence, moderate transitory renal dysfunction appears to develop nearly in every fifth patient in the early period after CABG. The risk factors for the development of postoperative renal dysfunction include: age, increased duration of the period of artificial circulation (AC) and time of aortic occlusion (AO), severe acute postoperative cardiac insufficiency, and re-sternotomy. Even moderately pronounced transitory renal dysfunction after CABG is associated with an unfavourable prognosis of in-hospital cardiovascular complications.

KEY WORDS: coronary artery bypass grafting, postoperative renal dysfunction, cardiovascular complications.

P. 129

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