Targeting Inflammation After Myocardial Infarction

PURPOSE OF REVIEW

Inflammation plays a key role in clearing cellular debris and recovery after acute myocardial infarction (AMI). Dysregulation of or prolonged inflammation may result in adverse cardiac remodeling and major adverse clinical events (MACE). Several pre-clinical studies and moderate sized clinical trials have investigated the role of immunomodulation in improving clinical outcomes in patients with AMI.

RECENT FINDINGS

Clinical data from the Canakinumab Atherothrombosis Outcome (CANTOS) and Colchicine Cardiovascular Outcomes Trial (COLCOT) have provided encouraging results among patients with AMI. Several other clinical and pre-clinical trials have brought about the prospect of modulating inflammation at various junctures of the inflammatory cascade including inhibition of complement cascade, interleukins, and matrix metalloproteinases. In patients with AMI, modulation of residual inflammation via various inflammatory pathways and mediators may hold promise for further reducing MACE. Learning from current data and understanding the nuances of immunomodulation in AMI are key for future trials and before widespread dissemination of such therapies.

Is there association between statin usage and contrast-associated acute kidney injury after intravenous administration of iodine-based contrast media in enhanced computed tomography?

OBJECTIVES

Contrast-induced acute kidney injury (CI-AKI) is one of the leading causes of new-onset renal failure in hospitalized patients. Statin has been evaluated for its protective effect against CI-AKI but rarely in patients receiving intravenous (IV) administrations of iodine-based contrast media for enhanced computed tomography (CT).

METHODS

In total, 12,371 patients who underwent contrast-enhanced abdominopelvic CT were retrospectively reviewed and stratified into statin users and statin nonusers. Subgroup analyses comparing high-intensity statins with low- to moderate-intensity statins were conducted within statin users and similar comparisons were performed within statin users stratified based on baseline eGFR.

RESULTS

Overall, CI-AKI events did not occur less in statin users compared with non-statin users (p = 0.342). Within statin users, CI-AKI events did not decrease in high-intensity statin users compared with low- to moderate-intensity statin users (p = 0.355). Moreover, no significant difference in CI-AKI events was found between high-intensity statin users and low- to moderate-intensity statin users even after stratifying the patients with baseline eGFR.

CONCLUSIONS

Collectively, statin was not significantly associated with the risk of CI-AKI events in patients undergoing contrast-enhanced abdominopelvic CT and high-intensity statins did not show significant association with CI-AKI over low- to moderate-intensity statins in the subgroup analysis.

KEY POINTS

• Statin is not associated with risk of CI-AKI events in patients undergoing intravenous administration of contrast-enhanced CT. • CI-AKI incidence among high-intensity statin users was not significantly different from that of low- to moderate-intensity statin users.

Pharmacologic Prophylaxis of Contrast-Induced Nephropathy

Different pharmacologic agents have been tested in the effort to prevent contrast-induced acute kidney injury (AKI) in the last two decades. To date, however, no individual drug has received unanimous approval for this aim. Since 2014 statins have been included as preventive treatment in the European guidelines for revascularization procedures in cardiac patients. The present update presents the latest findings in this field focusing on the changing paradigms in the definition and consequently the approach to nephroprotection that considers clinical prognosis as the major issue. We note the current shift from attention to contrast-induced AKI to contrast-associated AKI.

Laboratory Predictors of Contrast-Induced Nephropathy After Neurointervention: A Prospective 3-Year Observational Study

OBJECTIVE

The purpose of this study was to assess the natural course of contrast-induced nephropathy (CIN) and to determine the predictive abilities of preprocedural high-sensitivity C-reactive protein (hs-CRP) and urine neutrophil gelatinase-associated lipocalin for CIN after neurointervention procedures.

METHODS

We prospectively enrolled 176 patients who underwent an elective neurointervention procedure (diagnostic angiography or endovascular surgery). CIN was defined as an increase in serum creatinine of more than 0.5 mg/dL or an increase of at least 25% from the baseline value within 48 hours of contrast media exposure. The predictive value of hs-CRP and serial urine NGAL (baseline, 6, 24, and 48 hours) for the risk of CIN was assessed using multivariate logistic regression.

RESULTS

CIN occurred in 17 patients (9.46%). Multivariate analysis revealed that the CIN incidence was significantly associated with high baseline hs-CRP. All patients with CIN had creatinine return to baseline levels within 7 days. No patients required dialysis or suffered permanent sequelae as a result of a creatinine increase. During the 3-year follow-up period, no cerebro- or cardiovascular events occurred in the CIN group. However, 3 patients in the non-CIN group suffered a vascular event. One was a myocardial infarction, and 2 were ischemic strokes.

CONCLUSIONS

The incidence of CIN after neurointervention procedures was relatively high (9.46%). The natural course of CIN was favorable, however, and did not affect cerebrovascular events. Additionally, patients with CIN typically recovered with supportive care within 7 days. Elevated preprocedural hs-CRP levels (>5 mg/dL) were a significant and independent predictor of CIN after neurointervention procedures.

Contrast Induced Acute Kidney Injury and Direct Cytotoxicity of Iodinated Radiocontrast Media on Renal Proximal Tubule Cells

The administration of intravenous iodinated radiocontrast media (RCM) to visualize internal structures during diagnostic procedures has increased exponentially since their first use in 1928. A serious side effect of RCM exposure is contrast-induced acute kidney injury (CI-AKI), which is defined as an abrupt and prolonged decline in renal function occurring 48-72 hours after injection. Multiple attempts have been made to decrease the toxicity of RCM by altering ionic strength and osmolarity, yet there is little evidence to substantiate that a specific RCM is superior in avoiding CI-AKI. RCM-associated kidney dysfunction is largely attributed to alterations in renal hemodynamics, specifically renal vasoconstriction; however, numerous studies indicate direct cytotoxicity as a source of epithelial damage. Exposure of in vitro renal proximal tubule cells to RCM has been shown to affect proximal tubule epithelium in the following manner: 1) changes to cellular morphology in the form of vacuolization; 2) increased production of reactive oxygen species, resulting in oxidative stress; 3) mitochondrial dysfunction, resulting in decreased efficiency of the electron transport chain and ATP production; 4) perturbation of the protein folding capacity of the endoplasmic reticulum (ER) (activating the unfolded protein response and inducing ER stress); and 5) decreased activity of cell survival kinases. The present review focuses on the direct cytotoxicity of RCM on proximal tubule cells in the absence of in vivo complications, such as alterations in renal hemodynamics or cytokine influence.

Pre-Procedural N-Terminal Pro-B Type Natriuretic Peptide Predicts Contrast-Induced Acute Kidney Injury and Long-Term Outcome in Elderly Patients After Elective Percutaneous Coronary Intervention

The aim of the study is to evaluate the association of pre-procedural N-terminal pro-B type natriuretic peptide (NT-proBNP) with contrast-induced acute kidney injury (CI-AKI) and long-term outcomes in elderly patients undergoing elective percutaneous coronary intervention (PCI).A total of 540 patients aged ≥ 75 years who had undergone elective PCI between January 2012 and December 2015 were enrolled in this study. Admission NT-proBNP levels were measured before PCI. CI-AKI was defined as a relative increase in serum creatinine (SCr) of ≥50%, or an absolute increase of ≥ 0.3 mg/dL, occurring within 48 hours after contrast medium exposure. The predictive value of NT-proBNP for predicting CI-AKI was assessed by receiver operating characteristic (ROC) and multivariable logistic regression analysis.A total of 54 (10.0%) patients developed CI-AKI. The best cutoff value of NT-pro-BNP for detecting CI-AKI was 1133 pg/mL with 66.7% sensitivity and 70.8% specificity according to the ROC analysis (C statistic = 0.719; 95% CI, 0.679-0.756). Multivariable analysis demonstrated that Lg-NT-proBNP is significantly related to CI-AKI (odds ratio [OR] = 3.892; 95% CI, 1.996-7.590; P < 0.001). Cox regression analysis showed that Lg-NT-proBNP is associated with long-term mortality (adjusted hazard ratio [HR] = 2.158; 95% CI, 1.246-3.740; P = 0.006) during follow-up.Pre-procedural NT-proBNP is a significant and independent predictor of CI-AKI and long-term mortality in elderly patients following elective PCI, and the best cutoff point for predicting CI-AKI was 1133 pg/mL.

Primary Coronary Intervention in Octogenarians and Nonagenarians With ST-Segment Elevation Myocardial Infarction: A Canadian Single-Center Perspective

The proportion of individuals >80 years of age constitute an increasing proportion of patients who present with ST-segment elevation myocardial infarction (STEMI). The objective of this study is to evaluate in-hospital outcomes and 1-year survival of very elderly patients who present with an STEMI and undergo primary percutaneous coronary intervention (pPCI). Between 2009 and 2015, individuals >80 years of age (very elderly patients) with an STEMI presenting at a single tertiary Canadian care center were included in the study. A random sample of 100 individuals aged 65 to 69 years over the same time period were selected as a control group. A total of 284 patients were included in the study population including 100 controls, 164 octogenarians, and 20 nonagenarians. Of total, 1661 pPCIs occurred during this study period with the very elderly population (>80 years) comprising 11.1% of the total pPCIs. Compared with controls, individuals aged >80 are more likely to have a delay in treatment with increased rates of bleeding, acute kidney injury, rehospitalization, and a trend toward longer hospital stays following pPCI for STEMI. Although in-hospital and 1-year mortality were similar between both cohorts >80 years of age with STEMI, their overall survival was reduced compared with controls.

Contrast media-induced nephropathy: how has Italy contributed in the past 30 years? A systematic review

Background and objective

The use of contrast media in Italy has exponentially increased in the past 3 decades. However, it is unknown whether there has been an increase in clinical research evaluating the risks associated with contrast media usage, especially regarding contrast-induced nephropathy. To fill this gap in knowledge, we performed a systematic review.

Study eligibility criteria

Meta-analyses, observational studies, and clinical trials assessing contrast media-induced nephropathy as the safety outcome, in which at least one author was affiliated with an Italian university/health care structure, were eligble.

Data sources

Ovid MEDLINE, Ovid Embase, Cochrane Methodology Register, and Web of Science were screened.

Participants

Men and women exposed to contrast media.

Results

In total, 60 original articles were retrieved with an incremental trend between 1990 and 2017. Cohort studies were the most common study design represented. In total, 45 of 60 (75.0%) studies were monocenter studies and 41 of 60 (68.3%) received no funding. In all, 91.7% of studies disclosed no conflicts of interest and 81.7% had no external collaboration. Most of the studies provided a level of evidence of III-2 (32/60; 53.3%) and II (23/60; 38.3%). In total, 50 of 60 studies (83.3%) were published in a scientific journal ranked in the first quartile of their subject area.

Conclusion

There was an increased number of studies evaluating contrast-induced nephropathy in Italy during the last three decades. These studies covered procedures to prevent contrast-induced nephropathy or aimed to identify risk factors, biomarkers, and scores, and their related prognosis.

Contrast-Induced Acute Kidney Injury Is Associated With Long-Term Adverse Events in Patients With Acute Coronary syndrome

Contrast-induced acute kidney injury (CI-AKI) is associated with increased mortality, morbidity, and prolonged hospitalization. Patients with acute coronary syndrome (ACS) have a 3-fold higher risk of developing CI-AKI. The aim of our study was to evaluate the predictors of CI-AKI and long-term prognosis in patients with ACS who developed CI-AKI (1083 patients were enrolled). Contrast-induced acute kidney injury was defined as an increase of ≥0.5 mg/dL and/or an increase of ≥25% of pre-percutaneous coronary intervention (PCI) to post-PCI serum creatinine levels within 48 to 72 hours after the procedure. Primary end point was defined as all-cause mortality, myocardial infarction, and cerebrovascular event at long-term follow-up (36 ± 12 months). Contrast-induced acute kidney injury occurred in 178 (16.4%) of the 1083 patients. The primary end points were significantly high in patients with ACS who developed CI-AKI ( P < .001). The occurrence of CI-AKI was identified as an independent predictor of primary end point. Risk of CI-AKI development was more frequently seen in patients with ACS. Also, patients who developed CI-AKI have worse prognosis at long-term follow-up. Additional preventive treatment strategies need to be developed in this group of patients.

Salvianolic Acid B Prevents Iodinated Contrast Media-Induced Acute Renal Injury in Rats via the PI3K/Akt/Nrf2 Pathway

Contrast-induced acute renal injury (CI-AKI) has become a common cause of hospital-acquired renal failure. However, the development of prophylaxis strategies and approved therapies for CI-AKI is limited. Salvianolic acid B (SB) can treat cardiovascular-related diseases. The aim of the present study was to assess the effect of SB on prevention of CI-AKI and explore its underlying mechanisms. We examined its effectiveness of preventing renal injury in a novel CI-AKI rat model. Compared with saline, intravenous SB pretreatment significantly attenuated elevations in serum creatinine and the histological changes of renal tubular injuries, reduced the number of apoptosis-positive tubular cells, activated Nrf2, and lowered the levels of renal oxidative stress induced by iodinated contrast media. The above renoprotection of SB was abolished by the PI3K inhibitor (wortmannin). In HK-2 cells, SB activated Nrf2 and decreased the levels of oxidative stress induced by hydrogen peroxide and subsequently improved cell viability. The above cytoprotection of SB was blocked by the PI3K inhibitor (wortmannin) or siNrf2. Thus, our results demonstrate that, due to its antioxidant properties, SB has the potential to effectively prevent CI-AKI via the PI3K/Akt/Nrf2 pathway.