Short-term outcomes of acute myocardial infarction in patients with acute kidney injury: a report from the national cardiovascular data registry

Association between N-terminal pro-brain natriuretic peptide levels and contrast-induced nephropathy in patients undergoing percutaneous coronary intervention for acute coronary syndrome

BACKGROUND

Contrast-induced nephropathy (CIN) is associated with significantly increased morbidity and mortality after percutaneous coronary intervention (PCI). Patients with acute coronary syndrome (ACS) are at higher risk for CIN. N-terminal pro-brain natriuretic peptide (NT-proBNP) is closely linked to the prognosis as a strong predictor of both short- and long-term mortality in patients with ACS.

HYPOTHESIS

We hypothesized that NT-proBNP levels on admission can predict the development of CIN after PCI for ACS.

METHODS

A total of 436 patients (age 62.27 ± 13.01 years; 64.2% male) with ACS undergoing PCI enrolled in this study. Admission NT-proBNP levels were measured before PCI. Serum creatinine values were measured before and within 72 hours after the administration of contrast agents. Patients were divided into 2 groups: CIN group and no-CIN group. CIN was defined as an increase in serum creatinine level of ≥0.5 mg/dL or ≥25% above baseline within 72 hours after contrast administration.

RESULTS

CIN developed in 63 patients (14.4%). Baseline NT-proBNP levels were significantly higher in patients who developed CIN compared to those who did not develop CIN (median 774 pg/mL, interquartile range 177.4-2184 vs median 5159 pg/mL, interquartile range 2282-9677, respectively; P < 0.001). Multivariate analysis found that NT-proBNP (odds ratio [OR]: 3.448, 95% confidence interval [CI]: 1.394-8.474, P = 0.007) and baseline creatinine (OR: 6.052, 95% CI: 1.860-19.686, P = 0.003) were independent predictors of CIN.

CONCLUSIONS

Admission NT-proBNP level is an independent predictor of the development of CIN after PCI in ACS.

The incidence of kidney injury for patients treated with a high-potency versus moderate-potency statin regimen after an acute coronary syndrome

BACKGROUND

Observational studies have raised concerns that high-potency statins increase the risk of acute kidney injury. We therefore examined the incidence of kidney injury across 2 randomized trials of statin therapy.

METHODS AND RESULTS

PROVE IT-TIMI 22 enrolled 4162 subjects after an acute coronary syndrome (ACS) and randomized them to atorvastatin 80 mg/day versus pravastatin 40 mg/day. A-to-Z enrolled 4497 subjects after ACS and randomized them to a high-potency (simvastatin 40 mg/day × 1 months, then simvastatin 80 mg/day) versus a delayed moderate-potency statin strategy (placebo × 4 months, then simvastatin 20 mg/day). Serum creatinine was assessed centrally at serial time points. Adverse events (AEs) relating to kidney injury were identified through database review. Across both trials, mean serum creatinine was similar between treatment arms at baseline and throughout follow-up. In A-to-Z, the incidence of a 1.5-fold or ≥ 0.3 mg/dL rise in serum creatinine was 11.4% for subjects randomized to a high-potency statin regimen versus 12.4% for those on a delayed moderate-potency regimen (odds ratio [OR], 0.91; 95% confidence interval [CI], 0.76 to 1.10; P=0.33). In PROVE IT-TIMI 22, the incidence was 9.4% for subjects randomized to atorvastatin 80 mg/day and 10.6% for subjects randomized to pravastatin 40 mg/day (OR, 0.88; 95% CI, 0.71 to 1.09; P=0.25). Consistent results were observed for different kidney injury thresholds and in individuals with diabetes mellitus or with moderate renal dysfunction. The incidence of kidney injury-related adverse events (AEs) was not statistically different for patients on a high-potency versus moderate-potency statin regimen (OR, 1.06; 95% CI, 0.68 to 1.67; P=0.78).

CONCLUSIONS

For patients enrolled in 2 large randomized trials of statin therapy after ACS, the use of a high-potency statin regimen did not increase the risk of kidney injury.

The Influence of Acute Kidney Injury on Acute Cardiovascular Disease

Acute kidney injury (AKI) is an important issue in the management of acute cardiovascular diseases. The risk, injury, failure, loss of kidney function, and end-stage renal failure (RIFLE) criteria, and acute kidney injury network (AKIN) criteria have been proposed to stage and predict the outcomes of patients with AKI. In this article, we review AKI in the context of a variety of acute cardiovascular diseases, e.g., acute myocardial infarction (AMI), myocarditis, aortic dissection, and post-cardiotomy cardiogenic shock. For earlier detection of AKI, numerous biomarkers have been proposed and Cystatin C has been shown to have predictive value for AKI in patients with AMI.

KEY WORDS

Acute cardiovascular disease; Acute kidney injury.

Acute kidney injury after coronary artery bypass grafting and long-term risk of myocardial infarction and death

BACKGROUND

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) is associated with early mortality. Its impact on the risk of myocardial infarction (MI) over time and long-term mortality has not been well described.

METHODS

We performed a nationwide population-based cohort study in 27,929 patients who underwent a first isolated CABG between 2000 and 2008 in Sweden. Acute kidney injury was divided into three categories based on the absolute increase in postoperative serum creatinine (sCr) concentration compared with the preoperative baseline: stage 1, sCr increase of 0.3 to 0.5mg/dL; stage 2, sCr increase of >0.5 to 1.0mg/dL and stage 3, sCr increase of ≥ 1.0mg/dL.

RESULTS

The overall incidence of postoperative AKI was 13%, 6.3% met the criterion for stage 1, 4.3% for stage 2 and 2.3% for stage 3. During a mean follow-up of 5.0 years, there were 2119 (7.6%) MIs and 4679 (17%) deaths. Multivariable adjusted hazard ratios with 95% confidence intervals for MI were 1.35 (1.15 to 1.57), 1.80 (1.53 to 2.13) and 1.63 (1.29 to 2.07), in AKI stages 1, 2 and 3, respectively. The corresponding hazard ratios for all-cause mortality were 1.30 (1.17 to 1.44), 1.65 (1.48 to 1.83) and 2.68 (2.37 to 3.03), respectively.

CONCLUSIONS

Our results show that AKI after CABG is associated with an increased long-term risk of MI and death.

Trends in acute kidney injury and outcomes after early percutaneous coronary intervention in patients ≥75 years of age with acute myocardial infarction

We analyzed the Nationwide Inpatient Sample database from 2002 to 2010 to examine the temporal trends in incidence of acute kidney injury (AKI), AKI requiring dialysis, and associated in-hospital mortality in patients ≥75 years of age hospitalized with acute myocardial infarction and undergoing early (within 24 hours) percutaneous coronary intervention. Of 2,225,707 patients ≥75 years of age with acute myocardial infarction, 233,508 (10.5%) underwent early percutaneous coronary intervention, of which 21,961 (9.4%) developed AKI and 1,257 (0.54%) developed AKI requiring dialysis. From 2002 to 2010, the incidence of AKI increased from 5.6% to 14.2% (p for trend <0.001) and that for AKI requiring dialysis decreased (0.6% to 0.4%; p for trend 0.018). Compared with 2002, multivariable-adjusted odds ratios and 95% confidence intervals for AKI, AKI requiring dialysis, and in-hospital mortality in 2010 were 1.87 (1.71 to 2.05), 0.20 (0.15 to 0.27) and 0.74 (0.60 to 0.90), respectively. In conclusion, among hospitalized adults ≥75 years of age, from 2002 to 2010, there was an increase in AKI, but there was paradoxical decrease in AKI requiring dialysis and in-hospital mortality, potentially reflecting increased health-care provider awareness resulting in early recognition and implementation of renal-protective strategies and diagnosis-related group creep.

Kidney Disease Improving Global Outcomes or creatinine kinetics criteria in acute kidney injury: a proof of concept study

BACKGROUND

It has been recently mathematically demonstrated that the percentage increase in serum creatinine (SCr) can delay acute kidney injury (AKI) diagnosis in patients with previous chronic kidney disease (CKD). Based on creatinine (Cr) kinetics, it was suggested a new AKI classification using absolute increase in SCr elevation over specified time periods. However, this classification has not been evaluated in clinical studies.

METHODS

A prospective cohort study evaluated myocardial infarction patients during the first 7 days of hospital stay with daily SCr measurements. They were classified using Kidney Disease Improving Global Outcomes (KDIGO) and Cr kinetics systems. Both classifications were compared by net reclassification improvement (NRI) and area under the receiver operator characteristic (AuROC) curve regarding hospital mortality.

RESULTS

A total of 584 patients were included, of which 34.1% had previous CKD. Patients had more AKI by KDIGO than by Cr kinetics criteria (25.7 versus 18.0%, P < 0.001) and 81 patients (13.9%) had different AKI severity classification. Patients with AKI by KDIGO criteria and non-AKI by Cr kinetics had higher hospital mortality rates than patients with non-AKI using both classifications [adjusted mortality odds ratios (ORs): 4.753; 95% confidence interval (CI): 1.119-9.023, P = 0.014]. In patients with previous CKD, NRI analysis was 6.2% favoring Cr kinetics criteria. However, there was no difference using the AuROC curve analysis. In patients with no previous CKD, NRI analysis was 33.0%, favoring KDIGO, and this was in accordance with a better AuROC curve (0.828 versus 0.664, P < 0.05).

CONCLUSIONS

AKI classification proposed by a Cr kinetics model can be superior when diagnosing patients with previous CKD. However, KDIGO had a better performance in patients with no previous CKD.

Acute kidney injury and long-term risk of stroke after coronary artery bypass surgery

BACKGROUND

Acute kidney injury (AKI) is associated with death, end-stage renal disease, and heart failure in patients with coronary heart disease. This study investigated the association between AKI and long-term risk of stroke.

METHODS AND RESULTS

50,244 patients who underwent coronary artery bypass grafting (CABG) in Sweden between 2000 and 2008 were identified from the SWEDEHEART registry. After exclusions 23,584 patients without prior stroke who underwent elective, primary, isolated, CABG were included. AKI was categorized according to absolute increases in postoperative creatinine values compared with preoperative values: stage 1, 0.3-0.5 mg/dL (26-44 μmol/L); stage 2, 0.5-1.0mg/dL (44-88 μmol/L); and stage 3, >1.0 mg/dL (≥88 μmol/L). Cox proportional hazards regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for stroke. There were 1156 (4.9%) strokes during a mean follow-up of 4.1 years. After adjustment for confounders, HRs (95% CIs) for stroke in AKI stages 1, 2 and 3 were 1.12 (0.89-1.39), 1.31 (1.04-1.66) and 1.31 (0.92-1.87), respectively, compared with no AKI. This association disappeared after taking death into account in competing risk analysis. There was a significant association between AKI and stroke in men (HR: 1.26 [1.05-1.50]) but not in women (HR: 1.07 [0.75-1.53]), and in younger (<65 years; HR: 1.57 [1.12-2.22]), but not elderly patients (HR: 1.17 [0.98-1.40]).

CONCLUSIONS

The long-term risk of stroke is weakly associated with AKI after primary isolated CABG, but this association is attenuated and not significant when considering death as a competing risk.

Comparison of absolute serum creatinine changes versus Kidney Disease: Improving Global Outcomes consensus definitions for characterizing stages of acute kidney injury

BACKGROUND

The Kidney Disease: Improving Global Outcomes (KDIGO) system for classification of acute kidney injury (AKI) severity utilizes a staging schema based on relative changes in serum creatinine (sCr) concentration and urine output. This study compares the in-hospital mortality associated with KDIGO-defined AKI stages and AKI stages defined by absolute sCr increases ('Delta-Creatinine').

METHODS

The study included an analysis of hospital discharge and laboratory data from an urban academic medical center over a 1-year period. Including adult in-patients undergoing two or more sCr measurements, the study classified AKI stages using the KDIGO consensus standards as well as absolute increases in sCr ('Delta-Creatinine'); Stage 0, sCr increase <0.3 mg/dL, Stage 1, sCr increase 0.3-0.69 mg/dL, Stage 2, sCr increase 0.7-1.19 mg/dL and Stage 3, sCr increase ≥1.2 mg/dL or initiation of renal replacement therapy. The Delta-Creatinine cut-points were defined to optimize discrimination of in-patient mortality between AKI stages. The associations between KDIGO and Delta-Creatinine AKI stages and in-hospital mortality were compared using the time-dependent hazard ratios (HRs) and the net reclassification improvement (NRI).

RESULTS

Of the 19 878 hospitalizations included in the analysis, the prevalence of AKI was 23.4% as defined by the KDIGO criteria. The Delta-Creatinine system discriminated the differences between adjacent AKI stages (i.e. 1 versus 0, 2 versus 1, 3 versus 3) earlier than the KDIGO system. The NRI between Delta-Creatinine and KDIGO for the prediction of mortality was 9.7% [95% confidence interval (CI) 6.2-13.2%]. Stratification by age, sex, race and history of chronic kidney disease (CKD) resulted in similar NRI values.

CONCLUSION

The Delta-Creatinine system, based on the absolute increases in sCr, provides a promising alternative to the KDIGO system for characterizing the severity of AKI and its associations with in-patient mortality.

Incidence and relevance of acute kidney injury in patients hospitalized with acute coronary syndromes

Acute kidney injury (AKI) occurs frequently in patients with acute coronary syndromes (ACS) and is associated with adverse short- and long-term outcomes. To date, however, no standardized definition of AKI has been used for patients with ACS. As a result, information on its true incidence and the clinical and prognostic relevance according to the severity of renal function deterioration are still lacking. We retrospectively studied 3,210 patients with ACS. AKI was identified on the basis of the changes in serum creatinine during hospitalization according to the AKI Network criteria. Overall, 409 patients (13%) developed AKI: 262 (64%) had stage 1, 25 (6%) stage 2, and 122 (30%) stage 3 AKI. In-hospital mortality was greater in patients with AKI than in those without AKI (21% vs 1%; p <0.001). The adjusted risk of death increased with increasing AKI severity. Compared to no AKI, the adjusted odds ratio for death was 3.5 (95% confidence interval 1.79 to 6.83) with stage 1 AKI and 31.2 (95% confidence interval 16.96 to 57.45) with stage 2 to 3 AKI. A significant parallel increase in major adverse cardiac events was also observed comparing patients without AKI and those with stage 2 to 3 AKI. In conclusion, in patients with ACS, AKI is a frequent complication, and the graded increase of its severity, as assessed using the AKI Network classification, is associated with a progressive increased risk of in-hospital morbidity and mortality.

Acute kidney injury following coronary artery bypass surgery and long-term risk of heart failure

BACKGROUND

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) is common and increases the risk of postoperative complications and mortality. There is little information on the association between AKI after CABG and long-term risk of incident heart failure (HF).

METHODS AND RESULTS

All patients (n=24 018) undergoing primary, isolated CABG in Sweden between 2000 and 2008 with complete information on pre- and postoperative serum creatinine values, and no prior hospitalization for HF were included. The postoperative increase in serum creatinine was used to define different stages of AKI: stage 1, 0.3 to 0.5 mg/dL; stage 2, 0.5 to 1 mg/dL; stage 3, >1 mg/dL. Hazard ratios with 95% confidence intervals were calculated for first hospitalization for HF for each stage of AKI using Cox proportional hazards regression. Twelve percent of the study population developed AKI. During a mean follow-up of 4.1 years, there were 1325 cases (5.5%) of incident HF. Hazard ratios with 95% confidence interval for HF in AKI stage 1, 2, and 3 were 1.60 (1.34-1.92), 1.87 (1.54-2.27), and 1.98 (1.53-2.57), respectively, after multivariable adjustment for age, sex, diabetes mellitus, estimated glomerular filtration rate, left ventricular ejection fraction, and myocardial infarction before surgery or during follow-up.

CONCLUSIONS

AKI is associated with increased long-term risk of HF after CABG. Patients with AKI after CABG should be followed closely to detect early changes in cardiac function.

Acute kidney injury risk in patients with ST-segment elevation myocardial infarction at presentation to the ED

INTRODUCTION

Acute kidney injury (AKI) is common in acute myocardial infarction (AMI) patients and has serious prognostic implications. The early identification of patients at risk of developing AKI at the emergency department (ED) can reduce its incidence.

METHODS

Patients with ST-segment elevation myocardial infarction (STEMI) at the ED were included. Associated factors playing a role at ED presentation and during hospitalization were collected, and independent risk factors of developing AKI were assessed.

RESULTS

Mean age among patients (n = 406, 69.7% male) was 62.5 ± 12.5 years. At ED admission, the mean glomerular filtration rate (GFR) was 70.5 ± 28.1 mL/min per 1.73 m(2), and 140 (34.5%) patients had a GFR <60 mL/min per 1.73 m(2). Eighty-three patients (20.4%) developed AKI: 47 (11.6%) with stage 1, 26 (6.4%) with stage 2 and 10 (2.5%) with stage 3. Mortality was 11.8% and was higher in patients with AKI (34.9% vs 5.9%, P < .0001). Univariate analysis disclosed age, reduced GFR at presentation, severe Killip class, heart rate and longer door-to-needle time as risk factors to develop AKI. Moreover, these patients received less β-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker in the ED. Multivariate analysis revealed that age, Killip class, heart rate, door-to-needle time, and β-blocker non-use were independent factors associated with AKI. These factors provided the ED physician with good accuracy in identifying patients at high risk of developing AKI.

CONCLUSION

Factors associated with AKI in STEMI patients allowed physicians to identify patients at high risk in the ED. Moreover, reduced door-to-needle time and β-blocker use were associated with renal protection in AMI patients.