Morbidity, mortality and economic burden of renal impairment in cardiac intensive care

Impact of renal dysfunction on the management and outcome of acute heart failure: results from the French prospective, multicentre, DeFSSICA survey

OBJECTIVES

Cardiorenal syndrome (CRS) is the combination of acute heart failure syndrome (AHF) and renal dysfunction (creatinine clearance (CrCl) ≤60 mL/min). Real-life data were used to compare the management and outcome of AHF with and without renal dysfunction.

DESIGN

Prospective, multicentre.

SETTING

Twenty-six academic, community and regional hospitals in France.

PARTICIPANTS

507 patients with AHF were assessed in two groups according to renal function: group 1 (patients with CRS (CrCl ≤60 mL/min): n=335) and group 2 (patients with AHF with normal renal function (CrCl >60 mL/min): n=172).

RESULTS

Differences were observed (group 1 vs group 2) at admission for the incidence of chronic heart failure (56.42% vs 47.67%), use of furosemide (60.9% vs 52.91%), insulin (15.52% vs 9.3%) and amiodarone (14.33% vs 4.65%); additionally, more patients in group 1 carried a defibrillator (4.78% vs 0%), had ≥2 hospitalisations in the last year (15.52% vs 5.81%) and were under the care of a cardiologist (72.24% vs 61.63%). Clinical signs were broadly similar in each group. Brain-type natriuretic peptide (BNP) and BNP prohormone were higher in group 1 than group 2 (1157.5 vs 534 ng/L and 5120 vs 2513 ng/mL), and more patients in group 1 were positive for troponin (58.2% vs 44.19%), had cardiomegaly (51.04% vs 37.21%) and interstitial opacities (60.3% vs 47.67%). The only difference in emergency treatment was the use of nitrates, (higher in group 1 (21.9% vs 12.21%)). In-hospital mortality and the percentage of patients still hospitalised after 30 days were similar between groups, but the median stay was longer in group 1 (8 days vs 6 days).

CONCLUSIONS

Renal impairment in AHF should not limit the use of loop diuretics and/or vasodilators, but early assessment of pulmonary congestion and close monitoring of the efficacy of conventional therapies is encouraged to allow rapid and appropriate implementation of alternative therapies if necessary.

The burden of major adverse cardiac events in patients with coronary artery disease

Background

Patients with a history of cardiovascular disease are at high risk of developing secondary major adverse cardiac events (MACE). This study aimed to identify independent predictors of MACE after hospital admission which could be used to identify of high-risk patients who may benefit from preventive strategies.

Methods

This study included 1,520 consecutive patients with coronary artery disease (CAD) (654 with acute coronary syndrome (ACS) and 866 with elective percutaneous coronary intervention (PCI) patients) who received PCI and/or stenting. MACE was defined as all-cause mortality or rehospitalization for a cardiovascular- related illness. Cardiovascular-related illnesses included heart failure, reinfarction (nonfatal), recurrence of angina pectoris and repeat PCI or coronary artery bypass graft.

Results

During a mean follow-up period of 32 months, 558 of the 1,520 patients developed at least one MACE. Cox regression analysis showed that the baseline clinical and biochemical variables which associated with MACE were age, being illiterate, a widow or widower, and/or economically dependent, having triple vessel disease, stent implantation, anemia, and/or diabetes mellitus, waist to hip ratio (WHR), diastolic blood pressure, fasting glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C), creatinine, estimated glomerular filtration rate (eGFR), red blood cell count, hemoglobin, hematocrit, and mean corpuscular-hemoglobin concentration (MCHC) in ACS patients, and age, malnourished, and/or economically dependent, taking hypoglycemic medication, having triple vessel disease, stent implantation, anemia, diabetes mellitus, and/or hypertension, WHR, fasting glucose, HDL-C, uric acid, creatinine, eGFR, high-sensitivity C-reactive protein, mean corpuscular volume, and MCHC in elective PCI patients. Using multivariate Cox regression analysis, we found the MACE’s independent factors are triple vessel disease, stent implantation, hypertension, and eGFR in ACS patients, and having triple vessel disease, stent implantation, hypertension, and uric acid in elective PCI patients.

Conclusions

Having triple vessel disease, stent implantation, hypertension, and eGFR or uric acid independently predicted MACE in patients with CAD after long-term follow-up. Fortunately, these factors are modifiable and should be identified and monitored early.

Mortality and treatment costs of hospitalized chronic kidney disease patients between the three major health insurance schemes in Thailand

Background

Thailand has reformed its healthcare to ensure fairness and universality. Previous reports comparing the fairness among the 3 main healthcare schemes, including the Universal Coverage Scheme (UCS), the Civil Servant Medical Benefit Scheme (CSMBS) and the Social Health Insurance (SHI) have been published. They focused mainly on provision of medication for cancers and human immunodeficiency virus infection. Since chronic kidney disease (CKD) patients have a high rate of hospitalization and high risk of death, they also require special care and need more than access to medicine. We, therefore, performed a 1-year, nationwide, evaluation on the clinical outcomes (i.e., mortality rates and complication rates) and treatment costs for hospitalized CKD patients across the 3 main health insurance schemes.

Methods

All adult in-patient CKD medical expense forms in fiscal 2010 were analyzed. The outcomes focused on were clinical outcomes, access to special care and equipment (especially dialysis), and expenses on CKD patients. Factors influencing mortality rates were evaluated by multiple logistic regression.

Results

There were 128,338 CKD patients, accounting for 236,439 admissions. The CSMBS group was older on average, had the most severe co-morbidities, and had the highest hospital charges, while the UCS group had the highest rate of complications. The mortality rates differed among the 3 insurance schemes; the crude odds ratio (OR) for mortality was highest in the CSMBS scheme. After adjustment for biological, economic, and geographic variables, the UCS group had the highest risk of in-hospital death (OR 1.13;95 % confidence interval (CI) 1.07–1.20; p < 0.001) while the SHI group had lowest mortality (OR 0.87; 95 % CI 0.76–0.99; p = 0.038). The circumscribed healthcare benefits and limited access to specialists and dialysis care in the UCS may account for less favorable comparison with the CSMBS and SHI groups.

Conclusions

Significant differences are observed in mortality rates among CKD patients from among the 3 main healthcare schemes. Improvements in equity of care might minimize the differences.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-016-1792-9) contains supplementary material, which is available to authorized users.

Transcatheter aortic valve implantation in patients with pre-existing chronic kidney disease

BACKGROUND

We investigated the effect of chronic kidney disease (CKD) on morbidity and mortality following transcatheter aortic valve implantation (TAVI) including patients on haemodialysis, often excluded from randomised trials.

METHODS AND RESULTS

We performed a retrospective post hoc analysis of all patients undergoing TAVI at our centre between 2008 and 2012. 118 consecutive patients underwent TAVI; 63 were considered as having (CKD) and 55 not having (No-CKD) significant pre-existing CKD, (defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m²). Chronic haemodialysis patients (n = 4) were excluded from acute kidney injury (AKI) analysis. Following TAVI, in CKD and No-CKD patients respectively, AKI occurred in 23.7% and 14.5% (p = 0.455) and renal replacement therapy (RRT) was necessary in 8.5% and 3.6% (relative risk (RR) [95% CI] = 2.33 [0.47-11.5], p = 0.440); 30-day mortality rates were 6.3% and 1.8% (p = 0.370); and 1-year mortality rates were 17.5% and 18.2% (p = 0.919). Patients who developed AKI had a significantly increased risk of 30-day (12.5% vs. 1.1%, p = 0.029) mortality. We found the presence of diabetes (odds ratio (OR) [95% CI] = 4.58 [1.58-13.3], p = 0.005) and elevated baseline serum creatinine (OR [95% CI] = 1.02 [1.00-1.03], p = 0.026) to independently predict AKI to statistical significance by multivariate analysis.

CONCLUSION

TAVI is a safe, acceptable treatment for patients with pre-existing CKD, however caution must be exercised, particularly in patients with pre-existing diabetes mellitus and elevated pre-operative serum creatinine levels as this confers a greater risk of AKI development, which is associated with increased short-term post-operative mortality.

Prediction of contrast-induced nephropathy in patients with serum creatinine levels in the upper normal range by cystatin C: a prospective study in 374 patients

OBJECTIVE

Preexisting renal impairment is a risk factor for contrast-induced nephropathy (CIN). In patients with creatinine in the upper normal level, cystatin C might be a more sensitive predictor of CIN than creatinine. Therefore, in this study, we investigated the usefulness of cystatin C to predict CIN.

SUBJECTS AND METHODS

In 400 consecutive patients with creatinine baseline levels between 0.8 and 1.3 mg/dL undergoing coronary angiography (n = 200) or CT (n = 200), baseline values of cystatin C, creatinine, blood urea nitrogen (BUN) and risk factors of CIN were determined. Creatinine was also assessed 24 and 48 hours after contrast administration.

RESULTS

Creatinine significantly (p < 0.001) increased after 24 hours and 48 hours compared with baseline (1.06 ± 0.28 and 1.07 ± 0.28 vs 0.99 ± 0.18 mg/dL). Fifty-three of 373 evaluable patients (14.2%) had an increase in creatinine of ≥ 25% or ≥ 0.5 mg/dL within 48 hours. CIN according to this definition was significantly more frequent after intraarterial contrast administration (38/190, 20%) compared with IV contrast administration (15/183, 8.2%; p = 0.001). CIN was predicted by baseline cystatin C (area under the receiver operating characteristic [ROC] curve [AUC], 0.715; p < 0.001), whereas creatinine, creatinine clearance, and BUN were not predictive. The best predictive capabilities were provided by cystatin C/creatinine-ratio (AUC, 0.826; p < 0.001). Multivariate regression analysis showed that intraarterial contrast administration (p = 0.002) and higher baseline cystatin C (p < 0.001) combined with low creatinine (p = 0.044) were independently associated with higher increases in creatinine within 48 hours after contrast administration.

CONCLUSION

CIN in patients with creatinine within the upper normal range is significantly more frequent after intraarterial than after IV contrast administration. In these patients, renal impairment after contrast administration is independently predicted by cystatin C and cystatin C/creatinine-ratio, whereas BUN and creatinine were not predictive.

The risk of acute kidney injury and its impact on 30-day and long-term mortality after transcatheter aortic valve implantation

Background. Transcatheter aortic valve implantation (TAVI) is widely used in high risk patients (pts) with aortic stenosis. Underlying chronic kidney disease implicates a high risk of postprocedural acute kidney injury (AKI). We analyzed its occurrence, impact on hospital stay, and mortality. Methods. 150 consecutive pts underwent TAVI in our institution (mean age 81 ± 7 years; logistic EuroSCORE 24 ± 15%). AKI definition was a creatinine rise of 26.5 μmol/L or more within 48 hours postprocedural. Ten patients on chronic hemodialysis were excluded. Results. AKI occurred in 28 pts (20%). Baseline creatinine was higher in AKI pts (126.4 ± 59.2 μmol/L versus 108.7 ± 45.1 μmol/L, P = 0.09). Contrast media use was distributed evenly. Both, 30-day mortality (29% versus 7%, P < 0.0001) and long-term mortality (43% versus 18%, P < 0.0001) were higher; hospital stay was longer in AKI pts (20 ± 12 versus 15 ± 10 days, P = 0.03). Predicted renal failure calculated STS Score was similar (8.0 ± 5.0% [AKI] versus 7.1 ± 4.0% [non-AKI], P = 0.32) and estimated lower renal failure rates than observed. Conclusion. AKI remains a frequent complication with increased mortality in TAVI pts. Careful identification of risk factors and development of more suitable risk scores are essential.

Acute kidney injury: not just acute renal failure anymore?

Until recently, no uniform standard existed for diagnosing and classifying acute renal failure. To clarify diagnosis, the Acute Dialysis Quality Initiative group stated its consensus on the need for a clear definition and classification system of renal dysfunction with measurable criteria. Today the term acute kidney injury has replaced the term acute renal failure, with an understanding that such injury is a common clinical problem in critically ill patients and typically is predictive of an increase in morbidity and mortality. A classification system, known as RIFLE (risk of injury, injury, failure, loss of function, and end-stage renal failure), includes specific goals for preventing acute kidney injury: adequate hydration, maintenance of renal perfusion, limiting exposure to nephrotoxins, drug protective strategies, and the use of renal replacement therapies that reduce renal injury.

Cystatin C: a possible sensitive marker for detecting potential kidney injury after computed tomography coronary angiography

OBJECTIVES

Cystatin C (CyC) has recently been recognized as a sensitive marker for potential renal dysfunction. We investigated the role of CyC for evaluating potential kidney injury after computed tomography coronary angiography (CTCA).

METHODS

The CyC, serum creatinine (sCr), estimated glomerular filtration rate (eGFR), and blood urea nitrogen (BUN) levels were evaluated before and 1 day and 1 week after the procedure in 140 patients with preserved renal function referred for CTCA. The amount of unrestricted oral fluid intake was measured for 24 hours after CTCA. The relationship between the amount of oral fluid intake and the changes in each renal marker was compared.

RESULTS

A strong correlation was observed between oral fluid volume and the changes in CyC (r = -0.80, P < 0.0001) as well as the changes in sCr (r = -0.54, P < 0.0001) and eGFR (r = 0.57, P < 0.0001), but a weak correlation was observed between oral fluid volume and the changes in BUN (r = -0.22, P = 0.03). A progressive rise in a mean level of CyC was observed. The percentage of diabetic history was greater (73% vs 40%, P < 0.001) and oral fluid volume was lower (1142 mL vs 2114 mL, P < 0.0001) in patients with a rise in CyC but without one in sCr than in those showing a rise in neither CyC nor sCr at 1 day postprocedure. Seventy-four (80%) of 92 patients with a rise in CyC at 1 day postprocedure showed a recovery to the baseline sCr levels at 1 week postprocedure, but only 26 (28%) showed a recovery to the baseline CyC levels at 1 week.

CONCLUSIONS

Cystatin C is a more sensitive marker than sCr in evaluating the effects of oral fluid volume on renal function and in detecting potential kidney injury, especially in diabetic patients after CTCA.

Significant differences when using creatinine, modification of diet in renal disease, or cystatin C for estimating glomerular filtration rate in ICU patients

BACKGROUND

Renal dysfunction is associated with increased morbidity and mortality in intensive care patients. In most cases the glomerular filtration rate (GFR) is estimated based on serum creatinine and the Modification of Diet in Renal Disease (MDRD) formula, but cystatin C-estimated GFR is being used increasingly. The aim of this study was to compare creatinine and MDRD and cystatin C-estimated GFR in intensive care patients.

METHODS

Retrospective observational study was performed, on patients treated within the general intensive care unit (ICU) during 2004-2006, in a Swedish university hospital.

RESULTS

GFR markers are frequently ordered in the ICU; 92% of the patient test results had cystatin C-estimated GFR (eGFR(cystatinC)) ≤ 80 mL/min/1.73 m(2), 75% had eGFR ≤ 50 mL/min/1.73 m(2), and 30% had eGFR ≤ 20 mL/min/1.73 m(2). In contrast, only 46% of the patients had reduced renal function assessed by plasma creatinine alone, and only 47% had eGFR(MDRD) ≤ 80 mL/min/1.73 m(2). The mean difference between eGFR(MDRD) and eGFR(cystatinC) was 39 mL/min/1.73 m(2) for eGFR(cystatinC) values ≤ 60 mL/min/1.73 m(2).

CONCLUSIONS

GFR is commonly assessed in the ICU. Cystatin C-estimated GFR yields markedly lower GFR results than plasma creatinine and eGFR(MDRD). Many pharmaceuticals are eliminated by the kidney, and their dosage is adjusted for kidney function. Thus, the differences in GFR estimates by the methods used indicate that the GFR method used in the intensive care unit may influence the treatment.

Evolution of the coronary care unit: clinical characteristics and temporal trends in healthcare delivery and outcomes

OBJECTIVE

To describe long-term temporal trends in patient characteristics, processes of care, and in-hospital outcomes among unselected admissions within the contemporary coronary care unit.

DESIGN

Hospital administrative database that records both payment and operation data.

SETTING

Coronary care unit of a large, academic, tertiary-care medical institution.

PATIENTS

A total of 29,275 patients admitted from January 1, 1989 through December 31, 2006.

INTERVENTIONS

Unadjusted time-trend plots were created for all variables of interest, and multivariable modeling of coronary care unit death was performed.

MEASUREMENTS AND MAIN RESULTS

Temporal trends in Coronary Care Unit and in-hospital mortality, length-of-stay, demographic characteristics, discharge diagnoses, Coronary Care Unit procedures, and Charlson comorbidity scores were evaluated. Admission severity increased significantly over time (p < .001), but hospital length-of-stay decreased (p < .001). The proportion of coronary care unit admissions with non-ST-segment elevation myocardial infarction increased (p < .001), whereas ST-segment elevation myocardial infarction decreased (p < .001). The prevalence of non-cardiovascular diagnoses increased, with the rate greatest for comorbid critical illnesses, including sepsis, acute kidney injury, and respiratory failure (all p < .001). The use of non-cardiac procedures, such as mechanical ventilation and central venous catheterization, also increased over time (p < .001). Unadjusted coronary care unit and in-hospital mortality did not change during the study period, although death did decrease in the adjusted setting.

CONCLUSIONS

Substantial changes have occurred over time in patient characteristics, diagnoses, and procedures within the coronary care unit of a large, academic medical center. In particular, there have been significant increases in noncardiovascular critical illness, the results of which may be influencing patient outcomes. These findings underscore an existing need to clarify the role of the coronary care unit in contemporary cardiovascular care and to develop strategies for optimal training, staffing, and clinical investigation.

Use of drug-eluting stents in patients with coronary artery disease and renal insufficiency

Renal insufficiency (RI) has been shown to be associated with increased major adverse cardiovascular events after percutaneous coronary intervention. We reviewed the impact of RI on the pathogenesis of coronary artery disease and outcomes after percutaneous coronary intervention in the form of drug-eluting stent (DES) implantation in these high-risk patients. We searched the English-language literature indexed in MEDLINE, Scopus, and EBSCO Host research databases from 1990 through January 2009, using as search terms coronary revascularization, drug-eluting stent, and renal insufficiency. Studies that assessed DES implantation in patients with various degrees of RI were selected for review. Most of the available data were extracted from observational studies, and data from randomized trials formed the basis of a post hoc analysis. The outcomes after coronary revascularization were less favorable in patients with RI than in those with normal renal function. In patients with RI, DES implantation yielded better outcomes than did use of bare-metal stents. Randomized trials are needed to define optimal treatment of these high-risk patients with coronary artery disease.

Impact of biplane versus single-plane imaging on radiation dose, contrast load and procedural time in coronary angioplasty

Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose-area-product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4+/-121.0 Gycm(2)) than single-plane imaging (133.6+/-92.8 Gycm(2), p<0.0001). The difference was independent of case type (primary or elective) (p = 0.862), vascular territory (p = 0.519) and operator experience (p = 0.903). No significant difference was found in contrast load between biplane (166.8+/-62.9 ml) and single-plane imaging (176.8+/-66.0 ml) (p = 0.302). This non-significant difference was independent of case type (p = 0.551), vascular territory (p = 0.308) and operator experience (p = 0.304). Procedures performed with biplane imaging were significantly longer (55.3+/-27.8 min) than those with single-plane (48.9+/-24.2 min, p = 0.010) and, similarly, were not dependent on case type (p = 0.226), vascular territory (p = 0.642) or operator experience (p = 0.094). Biplane imaging resulted in a greater radiation dose and a longer procedural time and delivered a non-significant reduction in contrast load than single-plane imaging. These findings did not support the commonly perceived advantages of using biplane imaging in single-vessel coronary interventional procedures.

Importance of oral fluid intake after coronary computed tomography angiography: an observational study

BACKGROUND

The prevention of contrast-induced acute kidney injury (AKI) after coronary computed tomography angiography (CCTA) is important because patients referred for CCTA often need further contrast exposure such as an invasive coronary angiography. We aimed to examine the effects of oral volume intake on renal function in patients with preserved renal function referred for CCTA.

METHODS

We enrolled 180 patients who were referred for CCTA. The serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) levels were measured before, 24h, and a mean of 4.8 days after CCTA. The amount of unrestricted oral fluid intake for 24h was checked. The patients were divided into two groups: 106 subjects with a rise in SCr after CCTA (group A); and 74 without (group B).

RESULTS

Significant correlations were observed between the amount of oral fluid intake and the percentage changes in SCr (%SCr) (r=-0.66, p<0.0001) as well as the absolute changes in eGFR (ΔeGFR) (r=0.65, p<0.0001). The percentage of patients showing hemoglobin-A1c (HbA1c)≥6.5% was greater in group A than in group B (29% vs. 18%, p<0.001). Patients with HbA1c≥6.5% showed higher %SCr and lower ΔeGFR compared to those without it. Multiple regression analysis revealed that the amount of oral fluid intake was the only independent predictor for a rise in SCr (β=-0.731, p<0.0001).

CONCLUSION

Oral volume intake after CCTA is a very simple but important prophylactic procedure for contrast-induced AKI especially in diabetic patients.

Contrast-induced acute kidney injury

Cardiac angiography and coronary/vascular interventions depend on iodinated contrast media and consequently pose the risk of contrast-induced acute kidney injury (AKI). This is an important complication that accounts for a significant number of cases of hospital-acquired renal failure, with adverse effects on prognosis and health care costs. The epidemiology and pathogenesis of contrast-induced AKI, baseline renal function measurement, risk assessment, identification of high-risk patients, contrast medium use, and preventive strategies are discussed in this report. An advanced algorithm is suggested for the risk stratification and management of contrast-induced AKI as it relates to patients undergoing cardiovascular procedures. Contrast-induced AKI is likely to remain a significant challenge for cardiologists in the future because the patient population is aging and chronic kidney disease and diabetes are becoming more common.

Acute kidney injury with iodinated contrast

Diagnostic and interventional radiographic procedures in critically ill patients commonly depend on iodinated contrast media and consequently pose the risk of contrast-induced acute kidney injury. This is an important complication that accounts for a significant number of cases of hospital-acquired renal failure, with adverse effects on prognosis and healthcare costs. The epidemiology and pathogenesis of contrast-induced acute kidney injury, baseline renal function measurement, risk assessment, identification of high-risk patients, contrast medium use, and preventive strategies will be discussed in this article. An algorithm is suggested for the risk stratification and management of contrast-induced acute kidney injury as it relates to patients undergoing iodinated contrast exposure during critical illness. Contrast-induced acute kidney injury is likely to remain a significant challenge for intensivists in the future because the patient population is aging and chronic kidney disease and diabetes are becoming more common.

Improving the management of acute coronary syndromes in Australia: translating evidence to outcomes

Cardiovascular disease imposes a heavy burden of morbidity and mortality on the Australian community. This situation is likely to exacerbate as the number of elderly Australians increase. Management of acute coronary syndromes (ACS) is underpinned by a robust evidence base, which is outlined in clinical practice guidelines. Yet, despite wide diffusion of guidelines, many Australians who experience acute coronary syndromes do not receive optimal care. This article reviews what we have learnt from previous quality improvement initiatives and discusses what we need to know to improve acute coronary syndromes management in Australia.