Cardiac enzymes, renal failure and renal transplantation

Characterization of preoperative cardiovascular status and association with outcome following feline renal allograft transplantation: 166 cases

OBJECTIVES

To retrospectively evaluate preoperative historical, biochemical, and cardiovascular screening data for predictors of survival to discharge and long-term survival in feline renal allograft recipients from 1 institution.

ANIMALS

166 cats that underwent renal transplantation at the University of Pennsylvania between 1998 and 2018.

PROCEDURES

Medical records were reviewed for preoperative historical information, biochemical data, and cardiac assessment including auscultation findings, pre- and postoperative systolic blood pressure measurements, thoracic radiographic evaluation, and echocardiographic measurements. The need for hemodialysis, the number of surgical procedures, native kidney biopsy diagnosis and survival time was also recorded. Kaplan-Meier analysis was used to generate survival plots and estimate median survival times with a 95% CI. Univariable and multivariable analysis were performed to determine variables that were independently associated with survival to discharge and long-term survival.

RESULTS

The patient population primarily consisted of adult male DSH cats (70%) diagnosed with IRIS stage 4 CKD (66.3%). Abnormalities identified on preoperative cardiac assessment, including hypertension, the presence of a murmur, echocardiographic changes, and radiographic signs of congestive heart failure, were not associated with survival to discharge or long-term survival. Age was the only single significant variable associated with survival, and the risk of death increased by 11% (95% CI, 6% to 17%) for every 1 year in patient age.

CLINICAL RELEVANCE

The presence of cardiac abnormalities identified during the screening process of cats presenting for transplantation should not immediately exclude a potential candidate for the procedure. Owners considering transplantation should be educated on the impact of age on survival following surgery.

The Asia-Pacific Society of Cardiology (APSC) Expert Committee Consensus Recommendations for Assessment of Suspected Acute Coronary Syndrome Using High-Sensitivity Cardiac Troponin T in the Emergency Department

The Asia-Pacific Society of Cardiology (APSC) high-sensitivity troponin T (hs-TnT) consensus recommendations and rapid algorithm were developed to provide guidance for healthcare professionals in the Asia-Pacific region on assessing patients with suspected acute coronary syndrome (ACS) using a hs-TnT assay. Experts from Asia-Pacific convened in 2 meetings to develop evidence-based consensus recommendations and an algorithm for appropriate use of the hs-TnT assay. The Expert Committee defined a cardiac troponin assay as a high-sensitivity assay if the total imprecision is ≤10% at the 99th percentile of the upper reference limit and measurable concentrations below the 99th percentile are attainable with an assay at a concentration value above the assay's limit of detection for at least 50% of healthy individuals. Recommendations for single-measurement rule-out/rule-in cutoff values, as well as for serial measurements, were also developed. The Expert Committee also adopted similar hs-TnT cutoff values for men and women, recommended serial hs-TnT measurements for special populations, and provided guidance on the use of point-of-care troponin T devices in individuals suspected of ACS. These recommendations should be used in conjunction with all available clinical evidence when making the diagnosis of ACS.

Acute kidney injury is associated with microvascular myocardial damage following myocardial infarction

Acute kidney injury (AKI) is a frequent complication in patients with ST-elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention. However, the pathophysiology of AKI in this setting is complex and goes beyond the administration of contrast media. Studies assessing the impact of infarct characteristics on AKI are currently lacking. Therefore, we investigated the association of AKI with myocardial as well as microvascular injury in an initial total of 361 consecutive STEMI patients treated by primary percutaneous coronary intervention. Of these, 318 patients were included in final analysis. Serum creatinine was measured on admission as well as 24, 48, and 72 hours thereafter with AKI defined as an increase in serum creatinine of 0.3 mg/dl or more. Cardiac magnetic resonance (CMR) scans were performed in the first week after infarction, with microvascular injury visualized by late gadolinium enhancement CMR defined as any region of hypoenhancement within the hyperenhanced area of infarction. Sixteen patients developed AKI. They showed significantly lower left ventricular ejection fraction (45[interquartile range 40-52]% vs. 54[47-59]%), larger infarct size (21[15-35]% vs. 12[7-22]%) of left ventricular myocardial mass, and more frequent microvascular injury (81 vs. 46%) than those free of AKI. Meaningfully, in multivariate analysis including all CMR data, microvascular injury was the sole independent predictor of AKI (odds ratio 6.74, 95% confidence interval of 1.49-30.43). Thus, among revascularized STEMI patients, the presence of microvascular injury assessed by CMR was independently associated with an increased risk of AKI. This suggests a potential pathophysiological link between cardiac microvascular disease and renal injury following STEMI.

Short-term prognostic value of perioperative coronary sinus-derived-serum cardiac troponin-I, creatine kinase-MB, lactate, pyruvate, and lactate-pyruvate ratio in adult patients undergoing open heart surgery

OBJECTIVES

To investigate the release pattern of different cardiac metabolites and biomarkers directly from the coronary sinus (CS) and to establish the diagnostic discrimination limits of each marker protein and metabolites to evaluate perioperative myocardial injury in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB).

PATIENTS AND METHODS

Sixty-eight patients undergoing first mitral and/or aortic valve replacements with/without coronary artery bypass grafting and Bentall procedure under CPB and blood cardioplegic arrest were studied. All cardiac metabolites and biomarkers were measured in serial CS-derived blood samples at pre-CPB, immediate post aortic declamping, 10 minutes post-CPB and 12 hrs post-CPB.

RESULTS

Receiver operating characteristic curve analysis of cardiac biomarkers indicated lactate-pyruvate ratio as the superior diagnostic discriminator of myocardial injury with an optimal "cut-off" value >10.8 immediately after aortic declamping (AUC, 0.92; 95% CI: 0.85-0.98). Lactate was the second best diagnostic discriminator of myocardial injury with an optimal "cut-off" value >2mmol/l at immediately after aortic declamping (AUC, 0.89; 95% CI: 0.80-0.96). Cardiac troponin-I was the third best diagnostic discriminator of myocardial injury with an optimal "cut-off" value >2.1ng/ml at immediately after aortic declamping (AUC, 0.88; 95% CI: 0.80-0.95). Creatine kinase-MB was the fourth best diagnostic discriminator of myocardial injury with an optimal "cut-off" value >58 log units/ml prior to decanulation (AUC, 0.85; 95% CI: 0.78-0.94).

CONCLUSIONS

Measurable cardiac damage exists in all patients undergoing cardiac surgery under cardioplegic arrest. The degree of myocardial injury is more in patients with poor ventricular function and those requiring longer aortic clamp time. CS-derived lactate-pyruvate ratio, lactate, cTn-I served as superior diagnostic discriminators of peri-operative myocardial damage.

Renal Function and Scaled Troponin in Patients Presenting to the Emergency Department with Symptoms of Myocardial Infarction

BACKGROUND

Cardiac troponins are often found to be elevated in patients with renal dysfunction, even in the absence of acute myocardial injury. The objective of this report was to characterize the scaled troponin values and proportion of adjudicated acute myocardial infarction (AMI) among patients with and without renal dysfunction.

METHODS

The data was from a multicenter prospective study including patients presenting to the emergency department with symptoms of AMI. Troponin measurements were standardized across various assays by calculating the observed results as multiples of the assay-specific 99th percentile upper limit of normal. Patients with an estimated glomerular filtration rate (eGFR; calculated by the Chronic Kidney Disease Epidemiology Collaboration formula) <60 mL/min/1.73 m2 were considered to have renal dysfunction.

RESULTS

Of 430 included patients, 249 (58%) were male and 181 (42%) were female, with a mean age of 55.9 ± 12.3 and 57.3 ± 12.8 years, respectively. Eighty-seven (20.2%) had renal dysfunction. The proportions of patients with at least one scaled troponin value above the 99th percentile cut-off point among patients with and without renal dysfunction were 40 (45.9%) and 81 (23.6%) respectively (p < 0.001). The proportions of patients with an adjudicated diagnosis of AMI among those with and without renal dysfunction were 20.7 and 18.7%, respectively (p = 0.67). Using scaled troponins, by the second test there was >5X and by the third test >15X separation in the excursion of troponin among those with AMI compared to those without.

CONCLUSIONS

One or more elevated troponin values are common in those with renal dysfunction. Scaled troponins for eGFR groups were similar, indicating that the use of this interpretative technique is applicable in discerning AMI for those with and without renal dysfunction.

A Safe and Stable Neonatal Vaccine Targeting GAPDH Confers Protection against Group B Streptococcus Infections in Adult Susceptible Mice

Group B Streptococcus (GBS), a commensal organism, can turn into a life-threatening pathogen in neonates and elderly, or in adults with severe underlying diseases such as diabetes. We developed a vaccine targeting the GBS glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a glycolytic enzyme detected at the bacterial surface, which was proven to be effective in a neonatal mouse model of infection. Since this bacterium has emerged as an important pathogen in non-pregnant adults, here we investigated whether this vaccine also confers protection in an adult susceptible and in a diabetic mouse model of infection. For immunoprotection studies, sham or immunized adult mice were infected with GBS serotype Ia and V strains, the two most prevalent serotypes isolated in adults. Sham and vaccinated mice were also rendered diabetic and infected with a serotype V GBS strain. For toxicological (pre-clinical) studies, adult mice were vaccinated three times, with three concentrations of recombinant GAPDH adjuvanted with Allydrogel, and the toxicity parameters were evaluated twenty-four hours after the last immunization. For the stability tests, the vaccine formulations were maintained at 4°C for 6 and 12 months prior immunization. The results showed that all tested doses of the vaccine, including the stability study formulations, were immunogenic and that the vaccine was innocuous. The organs (brain, blood, heart, and liver) of vaccinated susceptible or diabetic adult mice were significantly less colonized compared to those of control mice. Altogether, these results demonstrate that the GAPDH-based vaccine is safe and stable and protects susceptible and diabetic adult mice against GBS infections. It is therefore a promising candidate as a global vaccine to prevent GBS-induced neonatal and adult diseases.

Nontraditional cardiovascular biomarkers and estimation of cardiovascular risk in predialysis chronic kidney disease patients and their correlations with carotid intima media thickness

Background:

Cardiovascular biomarkers such as N-terminal pro-B-type natriuretic peptide (NT-proBNP), cardiac troponin T (cTnT), hs-CRP (high sensitivity C-reactive protein), and albuminuria predict underlying heart disease in the general population as well as CKD patients.

Objectives:

We aimed to study the association of NT-proBNP, cTnT, hs-CRP, and spot urine albumin creatinine ratio with carotid intima media thickness (CIMT) for cardiovascular risk estimation in predialysis CKD (chronic kidney disease) patients.

Patients and Methods:

This cross-sectional study included a total of 120 adult predialysis CKD patients. Forty patients were allocated in each predialysis CKD group of stages 3, 4, and 5. Serum cTnT and hs-CRP, plasma NT-proBNP, and single spot urine albumin creatinine ratio (ACR) were measured. Ultrasonographic examination of carotid artery was done with 7.5 MHz linear probe in B mode ultrasonography and carotid intima media thickness was measured.

Results:

Mean values ± standard deviation of plasma NT-proBNP (pg/mL), serum hs-CRP (mg/L), spot urine ACR (mg/g of creatinine), and CIMT (mm) were 585.68 ± 514.84, 5.96 ± 2.52, 719.37 ± 411.36, and 0.78 ± 0.15, respectively in predialysis CKD patients (n = 120). Serum cTnT level was high in 40% of predialysis CKD patients. Among cardiovascular biomarkers, plasma NT-proBNP had maximum strength of correlation (Spearman Rho correlation coefficient; r = 0.575 and P < 0.0001) with the carotid intima media thickness followed by serum cTnT (Spearman Rho correlation coefficient; r = 0.419 and P < 0.0001), spot urine albumin creatinine ratio (Spearman Rho correlation coefficient; r = 0.322 and P < 0.0001), and serum hs-CRP (Spearman Rho correlation coefficient; r = 0.246 and P = 0.007).

Conclusions:

Nontraditional cardiovascular biomarkers such as plasma NT-proBNP, serum cTnT, serum hs-CRP, and spot urine ACR significantly correlate with CIMT. These biomarkers can estimate the cardiovascular risk in a predialysis CKD population with expected high cardiac morbidity and mortality.

Perioperative cardiac biomarkers: the utility and timing

PURPOSE OF REVIEW

We presume that biomarkers will improve identification of patients at risk, leading to interventions and treatments that reduce perioperative adverse events. Risk stratification is multifactorial, and a biomarker must add information to this process, thereby redistributing patients to either higher or lower risk categories, to improve the allocation of expensive and risky interventions. This review focuses on the utility of three cardiac biomarkers in perioperative management.

RECENT FINDINGS

Using newly defined epidemiologic criteria, three distinct molecules, brain natriuretic peptide (BNP), troponin (cTn), and glycosylated hemoglobin (HbA1c) emerge as potentially useful in perioperative medicine. A meta-analysis shows, in vascular surgery, BNP improves risk stratification. Four articles highlight the utility of postoperative cTn measurements in cases of myocardial injury. These articles show that most injury is not infarction, and they present preliminary evidence of the populations that will benefit from structured surveillance protocols. HbA1c is shown to improve the prediction of mortality, but there are questions whether this risk is modifiable.

SUMMARY

The findings here suggest an expanded role for postoperative cTn surveillance; however, the precise populations that benefit, or the interventions required, are not yet defined. The encouraging data for the other two biomarkers need more investigations before adopting them into routine clinical use.

Does percutaneous nephrolithotomy cause elevated cardiac troponins?

BACKGROUND

Percutaneous nephrolithotomy is the treatment of choice in large and staghorn renal stones, and myocardial infarction is one the possible complications during and after the surgery. We investigated if renal and skeletal muscle injury, caused by percutaneous nephrolithotomy, can cause elevation in cardiac troponins (cTn).

METHODS

This study was conducted on otherwise healthy patients with renal stone undergoing percutaneous nephrolithotomy. A baseline 12-lead electrocardiogram, echocardiography, and cTn assessment confirmed no cardiac pathology in any patients. Cardiac troponins T (cTnT) and I (cTnI), and also creatine kinase (CK) were assessed before and after surgery.

RESULTS

A total of 55 patients (69.1% males, mean age: 40.5 ± 13.8 year) were included. Serum creatinine level ranged from 0.7 to 1.3 mg/dl (mean = 1.03 ± 0.17). The level of CK was significantly increased by 469.5 ± 201.4 U/l (P < 0.001), and no positive cTnT or cTnI was observed after surgery.

CONCLUSION

The results of the present study showed that renal cell injury, caused by percutaneous nephrolithotomy, is not associated with elevated cardiac troponins. These findings show that increasing troponins in patients undergoing percutaneous nephrolithotomy indicate a cardiovascular pathology.

Visual enhancement of laparoscopic partial nephrectomy with 3-charge coupled device camera: assessing intraoperative tissue perfusion and vascular anatomy by visible hemoglobin spectral response

PURPOSE

We report the novel use of 3-charge coupled device camera technology to infer tissue oxygenation. The technique can aid surgeons to reliably differentiate vascular structures and noninvasively assess laparoscopic intraoperative changes in renal tissue perfusion during and after warm ischemia.

MATERIALS AND METHODS

We analyzed select digital video images from 10 laparoscopic partial nephrectomies for their individual 3-charge coupled device response. We enhanced surgical images by subtracting the red charge coupled device response from the blue response and overlaying the calculated image on the original image. Mean intensity values for regions of interest were compared and used to differentiate arterial and venous vasculature, and ischemic and nonischemic renal parenchyma.

RESULTS

The 3-charge coupled device enhanced images clearly delineated the vessels in all cases. Arteries were indicated by an intense red color while veins were shown in blue. Differences in mean region of interest intensity values for arteries and veins were statistically significant (p >0.0001). Three-charge coupled device analysis of pre-clamp and post-clamp renal images revealed visible, dramatic color enhancement for ischemic vs nonischemic kidneys. Differences in the mean region of interest intensity values were also significant (p <0.05).

CONCLUSIONS

We present a simple use of conventional 3-charge coupled device camera technology in a way that may provide urological surgeons with the ability to reliably distinguish vascular structures during hilar dissection, and detect and monitor changes in renal tissue perfusion during and after warm ischemia.

Increases of cardiac troponin in conditions other than acute coronary syndrome and heart failure

BACKGROUND

Although cardiac troponin (cTn) is a cornerstone marker in the assessment and management of patients with acute coronary syndrome (ACS) and heart failure (HF), cTn is not diagnostically specific for any single myocardial disease process. This narrative review discusses increases in cTn that result from acute and chronic diseases, iatrogenic causes, and myocardial injury other than ACS and HF.

CONTENT

Increased cTn concentrations have been reported in cardiac, vascular, and respiratory disease and in association with infectious processes. In cases involving acute aortic dissection, cerebrovascular accident, treatment in an intensive care unit, and upper gastrointestinal bleeding, increased cTn predicts a longer time to diagnosis and treatment, increased length of hospital stay, and increased mortality. cTn increases are diagnostically and prognostically useful in patients with cardiac inflammatory diseases and in patients with respiratory disease; in respiratory disease cTn can help identify patients who would benefit from aggressive management. In chronic renal failure patients the diagnostic sensitivity of cTn for ACS is decreased, but cTn is prognostic for the development of cardiovascular disease. cTn also provides useful information when increases are attributable to various iatrogenic causes and blunt chest trauma.

SUMMARY

Information on the diagnostic and prognostic uses of cTn in conditions other than ACS and heart failure is accumulating. Although increased cTn in settings other than ACS or heart failure is frequently considered a clinical confounder, the astute physician must be able to interpret cTn as a dynamic marker of myocardial damage, using clinical acumen to determine the source and significance of any reported cTn increase.