Association between urine pH and risk of contrast-associated acute kidney injury among patients after emergency percutaneous coronary intervention: a V-shape relationship?
AIM
We investigated whether perioperative urine pH was associated with contrast-associated acute kidney injury (CA-AKI) in patients undergoing emergency percutaneous coronary intervention (PCI).


METHODS
The study enrolled 1109 consecutive patients undergoing emergency PCI. Patients were divided into three groups based on perioperative urine pH (5.0-6.0, 6.5- 7.0, 7.5-8.5). The primary endpoint was the development of CA-AKI, defined as an absolute increase ≥ 0.3 mg/dL or a relative increase ≥ 50% from baseline serum creatinine within 48 h after contrast medium exposure.


RESULTS
Overall, 181 patients (16.3%) developed contrast-associated acute kidney injury. The incidences of CA-AKI in patients with urine pH 5.0-6.0, 6.5-7.0, and 7.5-8.5 were 19.7%, 9.8%, and 23.3%, respectively. After adjustment for potential confounding factors, perioperative urine pH 5.0-6.0 and 7.5-8.5 remained independently associated with CA-AKI [odds ratio (OR)1.86, 95% confidence interval (CI) 1.25-2.82, P = 0.003; OR 2.70, 95% CI 1.5-4.68, P < 0.001, respectively]. The association was consistent in subgroups of patients stratified by several CA-AKI risk predictors. However, the risk of CA-AKI associated with urine pH 7.5-8.5 was stronger in patients with worse renal function (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m2) (HR 5.587, 95% CI 1.178-30.599 vs. HR 2.487, 95% CI 1.331-4.579; overall interaction P < 0.05).


CONCLUSION
The urine pH and CA-AKI may underlie the V-shape relationship.
['Chen|Hanchuan|H|', 'He|Chen|C|', 'You|Zhebin|Z|', 'Zhang|Sicheng|S|', 'He|Haoming|H|', 'Chen|Xi Nan|XN|', 'Wang|Sunying|S|', 'Lin|Kaiyang|K|', 'Guo|Yansong|Y|http://orcid.org/0000-0001-6607-6938']
D058186:Acute Kidney Injury D000368:Aged D003287:Contrast Media D003404:Creatinine D004630:Emergencies D005260:Female D005919:Glomerular Filtration Rate D006801:Humans D006863:Hydrogen-Ion Concentration D008297:Male D008875:Middle Aged D062645:Percutaneous Coronary Intervention D059035:Perioperative Period D011446:Prospective Studies D012307:Risk Factors D015996:Survival Rate D014556:Urine
Urine pH Contrast-associated acute kidney injury Emergency percutaneous coronary intervention