Albuminuria in ischemic heart disease

Proteinuria associated with acute heart disease was studied prospectively in 160 patients admitted to the coronary care unit with suspected AMI. Series 1 comprised 150 patients, divided into the following groups: AMI, 27 UAP, 43 AP, 22 NIP and 18 excluded. Albumin and creatinine were measured in the first urine passed after admission (sample 1) and the first morning urine the following 2 days (samples 2 and 3). The ACR was significantly higher in the AMI and UAP groups than in the other patient groups (p < 0.0001). There was no significant difference of ACR between the AMI and UAP in sample 1 (p = 0.31). In the AMI, UAP and AP groups ACR was significantly higher in sample 1 than in samples 2 and 3 (p < 0.005). In the NIP group there were no significant differences between sample 1 versus samples 2 and 3 (p = 0.06). Series 2 comprised 10 patients: 8 AMI, 1 UAP and 1 AMYO. ACR were measured in all specimens voided during the period of observation. ACR can oscillate within hours between normal concentrations and concentrations well into or above the microalbuminuric range. We propose the term episodic albuminuria for this reversible, switch-like change in renal function. The albuminuric episodes lasted 90-600 minutes. Maximum values for ACR were between 133-790 mumol/mol or 78-466 mg/g. In healthy, resting individuals ACR is < 50 mumol/mol (< 30 mg/g). The rapid changes in glomerular permeability may reflect systemic changes in endothelial permeability in the affected individuals. We speculate that atrial natriuretic peptide (ANP) may be a mediator of this type of albuminuria.