Chart validation of inpatient ICD-9-CM administrative diagnosis codes for acute myocardial infarction (AMI) among intravenous immune globulin (IGIV) users in the Sentinel Distributed Database.

BACKGROUND: The Sentinel Distributed Database (SDD) is a large database of patient-level administrative health care records, primarily derived from insurance claims and electronic health records, and is sponsored by the US Food and Drug Administration for medical product safety evaluations. Acute myocardial infarction (AMI) is a common study endpoint for drug safety studies that rely on health records from the SDD and other administrative databases. PURPOSE: In this chart validation study, we report on the positive predictive value (PPV) of inpatient International Classification of Diseases, Ninth Revision, Clinical Modification AMI administrative diagnosis codes (410.x1 and 410.x0) in the SDD. METHODS: As part of an assessment of thromboembolic adverse event risk following treatment with intravenous immune globulin, charts were obtained for 103 potential post-intravenous immune globulin AMI cases. Charts were abstracted by trained nurses and physician-adjudicated based on prespecified diagnostic criteria. RESULTS: Acute myocardial infarction status could be determined for 89 potential cases. The PPVs for the inpatient AMI diagnoses recorded in the SDD were 75% overall (95% CI, 65-84%), 93% (95% CI, 78-99%) for principal-position diagnoses, 88% (95% CI, 72-97%) for secondary diagnoses, and 38% (95% CI, 20-59%) for position-unspecified diagnoses (eg, diagnoses originating from separate physician claims associated with an inpatient stay). Of the confirmed AMI cases, demand ischemia was the suspected etiology more often for those coded in secondary or unspecified positions (72% and 40%, respectively) than for principal-position AMI diagnoses (21%). CONCLUSIONS: The PPVs for principal and secondary AMI diagnoses were high and similar to estimates from prior chart validation studies. Position-unspecified diagnosis codes were less likely to represent true AMI cases.

Time to Wound Healing and Major Adverse Limb Events in Patients with Critical Limb Ischemia Treated with Endovascular Revascularization.

BACKGROUND: There are few studies that quantify the impact of time to wound healing on outcomes after endovascular revascularization of critical limb ischemia (CLI). METHODS: In this retrospective study, 179 patients with CLI and tissue loss were assessed for adverse events after endovascular therapy. Associations between time to wound healing and outcomes were determined via Cox proportional hazards analysis. The long-term probability of events was assessed with Kaplan-Meier analysis. The primary end point was major adverse limb events (MALE-major amputation, surgical endarterectomy, or bypass). Secondary end points were major amputation, need for repeat endovascular therapy, and mortality. RESULTS: After multivariable adjustment for time-dependent wound healing, age, renal function, diabetes, and Rutherford class, independent predictors of MALE included the presence of an unhealed wound (hazard ratio [HR], 5.2; 95% confidence interval (CI), 2.3-11.8; P < 0.0001) and creatinine ≥ 2.0 (HR, 2.4; 95% CI, 1.4-4.3; P = 0.003). On Kaplan-Meier analysis, the probability of MALE was greater in patients with unhealed wounds compared with healed wounds (log-rank P < 0.0001). Patients whose wounds healed within 4 months had a lower probability of MALE than patients who did not heal by 4 months (log-rank, P = 0.04). Unhealed wounds were also independently associated with major amputation (HR, 9.0; 95% CI, 2.6-31.1; P = 0.0004), and patients whose wounds healed by 3 months had less major amputation (log-rank, P = 0.04). Unhealed wounds were independently associated with increased risk of mortality (HR, 42.7; 95% CI, 5.7-319.0; P = 0.002) but not repeat revascularization. CONCLUSIONS: Unhealed wounds are an independent risk factor for MALE, major amputation, and mortality after endovascular treatment of CLI. Wound healing within 3 months is associated with less risk of major amputation, and within 4 months less risk of MALE. A focus should be on achieving wound healing as fast as possible in this population.

Hospital Readmissions Following Endovascular Therapy for Critical Limb Ischemia: Associations With Wound Healing, Major Adverse Limb Events, and Mortality.

BACKGROUND: The significance of hospital readmission after endovascular therapy for critical limb ischemia (CLI) is not well established. We sought to investigate the incidence, timing, and causes of readmissions after endovascular therapy for CLI and whether readmission is associated with major adverse limb events (MALE) or mortality. METHODS AND RESULTS: This was a retrospective study of 252 patients treated with endovascular therapy for CLI. During median follow-up of 381 days (interquartile range [IQR], 115-718), 140 (56%) were readmitted, with median time to readmission of 83 days (IQR, 33-190). Readmission within 30 days occurred in 14% of patients (n=35; 25% of readmissions). Most readmissions occurred between 30 and 180 days (n=67; 48% of readmissions). The most frequent reason for readmission was unhealed wounds (n=63; 45% of readmissions). Independent predictors of readmission by Cox proportional hazards analysis were unhealed wounds, presence of multiple wounds, age ≥70, female sex, hemodialysis, and history of heart failure (P<0.05 for each). By Kaplan-Meier analysis, readmission was greatest in patients with unhealed wounds, followed by patients who never had a wound, and lowest in patients whose wounds completely healed (P<0.0001 overall, and P<0.01 between groups). After multivariable adjustment, readmission remained an independent predictor of composite MALE (major amputation, bypass, or endarterectomy) or mortality (adjusted hazard ratio, 3.1; 95% CI, 1.5-6.5; P=0.002). CONCLUSIONS: Most readmissions occur 30 and 180 days after endovascular therapy for nonprocedural reasons. Unhealed wounds are an independent risk factor for readmission. Readmission is associated with increased MALE and mortality after endovascular therapy for CLI.