Impact of nephropathy after percutaneous coronary intervention and a method for risk stratification.

Radiocontrast-induced nephropathy (RCIN) after percutaneous coronary intervention (PCI) is associated with grave consequences, but risk stratification of patients has not been well elucidated. This analysis derived a time-insensitive score to predict the risk of RCIN after PCI. A derivation cohort (1993 to 1998) and a validation cohort (1999 to 2002) comprised 20,479 patients who underwent PCI. RCIN after PCI was defined as a >/=1.0 mg/dl increase in serum creatinine. Variables having an independent correlation for RCIN after PCI were used to derive the RCIN risk score from the derivation cohort and were tested in the validation cohort. RCIN occurred in 2% of patients after PCI. Independent variables (with weighted scores) include estimated creatinine clearance <60 ml/min (2), urgent PCI (2), intra-aortic balloon pump use (2), diabetes mellitus (1), congestive heart failure (1), hypertension (1), peripheral vascular disease (1), and contrast volume >260 ml (1). The incidence of RCIN after PCI increased with each unit increase in score (p <0.0001, concordance statistic 0.89). No patient with a score /=9 developed RCIN after PCI (p <0.0001). Propensity score analysis showed that patients who developed RCIN after PCI, irrespective of the need for hemodialysis, had higher in-hospital rates of major adverse cardiac events (odds ratio 15, 95% confidence interval 11 to 20, p <0.0001). RCIN occurred in 2.0% of PCI patients and was associated with a 15-fold increase in adverse cardiac events. The RCIN risk score was a clinical assessment tool with excellent predictive ability in identifying the larger population at risk for nephropathy in whom preventative strategies are indicated.

Simplified scoring system for predicting mortality after percutaneous coronary intervention.

OBJECTIVES: We sought to develop a simplified scoring system based on pre-intervention clinical characteristics to predict in-hospital mortality after percutaneous coronary intervention (PCI). BACKGROUND: Percutaneous coronary intervention is associated with variety of complications, including the risk of death. Factors leading to poor outcomes need to be identified. Currently available indexes are cumbersome and therefore seldom used. METHODS: Crude mortality and univariate odds ratios (ORs) for mortality associated with multiple clinical characteristics were calculated for 9,954 patients undergoing PCI at the William Beaumont Hospital during 1996 to 1998. Based on the OR, each factor was assigned a weighted score. Using these scores, a classification was constructed to determine the probability of death after PCI, with classes I through IV representing an increasing probability of procedural mortality. This classification was validated in a separate group of patients. RESULTS: The factors with the highest univariate odds of dying and their scores were: myocardial infarction <14 days = 7; elevated creatinine = 4; multivessel disease = 4; and age >65 years = 3. Classes were created based on the presence of these factors in a given patient. The odds of dying and mortality increased significantly with each class. These results were reproduced in the validation subset. CONCLUSIONS: Preprocedural clinical risk factors have a differential influence on the probability of death after PCI. Risk classification based on these factors can be used to accurately predict the procedural outcome. This simple classification can be used by interventionalists to assist in management decisions, to provide an estimate of procedural risk to the patients and relatives, and for quality assurance.