Blood pressure and renal outcomes in patients with kidney infarction and hypertension

Objective To assess the causes and frequency of kidney infarction associated with hypertension, and the blood pressure and renal function outcomes. Methods We analyzed the records of patients with kidney infarction documented by angiography and referred to a hypertension unit. Results Spontaneous kidney infarction was documented in 55 of 18 287 patients and was associated with renal artery disease in 41 cases. Twenty-five patients had a longstanding history of hypertension at referral, and 30 patients presented with acute hypertension. Patients with acute hypertension were more likely to report a history of lumbar pain and to develop malignant hypertension than patients with longstanding hypertension; they also had higher plasma renin concentrations. Data for long-term follow-up after referral were available for 36 patients, including 15 patients who underwent surgery or renal artery angioplasty. From referral to most recent follow-up, the blood pressure decreased from 176/111 to 143/89 mmHg in patients with longstanding hypertension, and from 183/111 to 127/80 mmHg in those with acute hypertension (P = 0.007/0.041 for between-group differences). Three patients with acute hypertension had normal blood pressure without treatment at follow-up. Patients with long-term follow-up displayed no change in the glomerular filtration rate. Conclusion Kidney infarction is a rare cause of hypertension, usually associated with renal artery lesions. In cases of kidney infarction with acute hypertension, the blood pressure outcome is favorable following intervention and/or medication, and hypertension may resolve spontaneously.