Lorenzo Azzalini

Contrast-Induced Nephropathy: From Pathophysiology to Preventive Strategies

Contrast-induced nephropathy (CIN) is a frequent cause of acute kidney injury in hospitalized patients. CIN is most commonly defined as either an absolute (≥ 0.5 mg/dL; ≥ 44 μmol/L) or relative (≥ 25%) increase in serum creatinine levels at 48-72 hours after exposure to iodinated contrast media (CM). Its occurrence is associated with worsened clinical outcomes. Patients undergoing cardiac catheterization and percutaneous coronary intervention are particularly vulnerable to CIN. The complex pathophysiology of CIN involves different mechanisms, such as vasoconstriction, oxidative stress, medullary ischemia, and the direct toxic effects of CM. In CIN pathophysiology, both patient-related and procedure-related risk factors have been identified. The risk for CIN can be reliably estimated with clinical scores such as that proposed by Mehran. Because no definitive treatment exists for CIN, the most effective strategy remains prevention. Several interventions have been investigated--from hydration to various pharmacologic agents and mechanical devices. In this state-of-the-art article, we review the pathophysiology, diagnosis, risk stratification, and preventive strategies for CIN.

Myths to Debunk to Improve Management, Referral, and Outcomes in Patients With Chronic Total Occlusion of an Epicardial Coronary Artery.

A chronic total occlusion (CTO) is defined as an occlusive (100% stenosis) coronary lesion with anterograde Thrombolysis In Myocardial Infarction 0 flow for at least 3 months. CTOs are common in patients referred for coronary angiography (up to 33%) and are associated with angina, impaired quality of life, and reduced survival. Unfortunately, CTO percutaneous coronary intervention continues to be underperformed worldwide (10% to 15% at most institutions, ∼30% where expert operators are available). The aim of this study was to address common fallacies pertaining to CTOs among cardiologists by providing a concise review of pertinent previously published reports along with an update on safety and efficacy of state-of-the-art CTO percutaneous coronary intervention techniques.

The Benefits Conferred by Radial Access for Cardiac Catheterization Are Offset by a Paradoxical Increase in the Rate of Vascular Access Site Complications With Femoral Access : The Campeau Radial Paradox

OBJECTIVES The purpose of this study was to assess whether the benefits conferred by radial access (RA) at an individual level are offset by a proportionally greater incidence of vascular access site complications (VASC) at a population level when femoral access (FA) is performed. BACKGROUND The recent widespread adoption of RA for cardiac catheterization has been associated with increased rates of VASCs when FA is attempted. METHODS Logistic regression was used to calculate the adjusted VASC rate in a contemporary cohort of consecutive patients (2006 to 2008) where both RA and FA were used, and compared it with the adjusted VASC rate observed in a historical control cohort (1996 to 1998) where only FA was used. We calculated the adjusted attributable risk to estimate the proportion of VASC attributable to the introduction of RA in FA patients of the contemporary cohort. RESULTS A total of 17,059 patients were included. At a population level, the VASC rate was higher in the overall contemporary cohort compared with the historical cohort (adjusted rates: 2.91% vs. 1.98%; odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.17 to 1.89; p = 0.001). In the contemporary cohort, RA patients experienced fewer VASC than FA patients (adjusted rates: 1.44% vs. 4.19%; OR: 0.33, 95% CI: 0.23 to 0.48; p < 0.001). We observed a higher VASC rate in FA patients in the contemporary cohort compared with the historical cohort (adjusted rates: 4.19% vs. 1.98%; OR: 2.16, 95% CI: 1.67 to 2.81; p < 0.001). This finding was consistent for both diagnostic and therapeutic catheterizations separately. The proportion of VASCs attributable to RA in the contemporary FA patients was estimated at 52.7%. CONCLUSIONS In a contemporary population where both RA and FA were used, the safety benefit associated with RA is offset by a paradoxical increase in VASCs among FA patients. The existence of this radial paradox should be taken into consideration, especially among trainees and default radial operators.

Direct Stenting Versus Pre‐Dilation in ST‐Elevation Myocardial Infarction: A Systematic Review and Meta‐Analysis

OBJECTIVES This study aimed at comparing direct stenting (DS) versus stenting with pre-dilation (SP) in patients with ST-elevation myocardial infarction (STEMI), using a systematic review and meta-analysis of published evidence. BACKGROUND There is conflicting evidence whether stenting strategy impacts clinical outcomes in patients with STEMI. METHODS We searched EMBASE, MEDLINE, and CENTRAL, from inception to December 2014. The primary endpoint was mortality. Secondary endpoints included major adverse cardiac events (MACEs), ST-segment resolution, and angiographic outcomes. RESULTS A total of 9,331 patients enrolled in 12 studies (3 randomized controlled trials, RCTs; 9 non-randomized studies, NRSs) were included. DS was associated with lower mortality (OR 0.55; 95%CI: 0.33-0.94; P = 0.03) in NRSs, and overall (OR 0.56; 95%CI: 0.37-0.86; P = 0.008). Mortality was non-significantly reduced in RCTs (OR 0.56; 95%CI: 0.26-1.23; P = 0.15). DS was also associated with lower MACE rate (OR 0.71; 95%CI 0.60-0.84; P < 0.0001) in NRSs, but not in RCTs (OR 0.99; 95%CI: 0.61-1.60; P = 0.96). ST-segment resolution, no reflow, final thrombolysis in myocardial infarction (TIMI) flow and final TIMI myocardial perfusion or blush grade were significantly better with DS in NRSs, and non-significantly better in RCTs. CONCLUSIONS The available evidence suggests that DS in STEMI might be associated with better clinical and procedural outcomes, as compared with SP. However, the fact that RCTs account for the minority of available data and that most of the available studies poorly reflect current clinical practice, as well as the existence of publication bias, preclude drawing definitive conclusions.

Procedural and longer-term outcomes of wire- versus device-based antegrade dissection and re-entry techniques for the percutaneous revascularization of coronary chronic total occlusions

BACKGROUND There are few data regarding the procedural and follow-up outcomes of different antegrade dissection/re-entry (ADR) techniques for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS We compiled a multicenter registry of consecutive patients undergoing ADR-based CTO PCI at four high-volume specialized institutions. Patients were divided according to the specific ADR technique used: subintimal tracking and re-entry (STAR), limited antegrade subintimal tracking (LAST), or device-based with the CrossBoss/Stingray system (Boston Scientific, Marlborough, MA). Major adverse cardiac events (MACE: cardiac death, target-vessel myocardial infarction and target-vessel revascularization) on follow-up were the main outcome of this study. Independent predictors of MACE were sought with Cox regression analysis. RESULTS A total of 223 patients were included (STAR n=39, LAST n=68, CrossBoss/Stingray n=116). Baseline characteristics were similar across groups. Technical and procedural success was lower with STAR (59% and 59%), as compared with LAST (96% and 96%) and CrossBoss/Stingray (89% and 87%; p<0.001 for both). At 24-month follow-up, MACE rates were higher in STAR (15.4%) and LAST (17.5%), as compared with device-based ADR with CrossBoss/Stingray (4.3%, p=0.02), driven by TVR (7.7% vs. 15.5% vs. 3.1%, respectively; p=0.02). Multivariable Cox regression analysis identified wire-based ADR (STAR and LAST) and total stent length as independent predictors of MACE. CONCLUSIONS In this multicenter cohort of patients undergoing CTO PCI with ADR techniques, STAR had lower success rates, as compared with the CrossBoss/Stingray system and LAST. The CrossBoss/Stingray system was independently associated with lower risk of MACE on follow-up, as compared with wire-based ADR techniques.

Impact of crossing strategy on midterm outcomes following percutaneous revascularisation of coronary chronic total occlusions

AIMS The aim of the present study was to compare the midterm clinical outcomes of patients undergoing successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) according to the crossing technique used, in a large multicentre registry. METHODS AND RESULTS We compiled a multicentre registry of consecutive patients undergoing successful CTO PCI. Patients were divided into three groups: true-to-true (TTT) approach, modern dissection/re-entry (DR) techniques (CrossBoss/Stingray, reverse CART), and old DR techniques (LAST, STAR, CART). Cox regression was used to identify independent predictors of major adverse cardiac events (MACE: cardiac death, myocardial infarction and target vessel revascularisation). We included 924 patients (TTT, n=571; modern DR, n=258; old DR, n=95). Patients in both DR groups had a higher prevalence of comorbidities, angiographic and procedural complexity. The 12-month MACE rate was higher in old DR (22.1%) than in modern DR (8.9%) and TTT (9.1%, p<0.001). Old (hazard ratio [HR] 2.02, 95% confidence interval [CI]: 1.12 to 3.61, p=0.02) but not modern (HR 0.98, 95% CI: 0.54 to 1.79, p=0.96) DR techniques were associated with a higher adjusted risk of MACE compared to TTT. CONCLUSIONS The use of old but not modern DR techniques was associated with a higher risk of MACE. Therefore, CrossBoss/Stingray and reverse CART might be considered as first-line strategies for antegrade and retrograde DR-based CTO PCI, respectively.

Procedural and Long-Term Outcomes of Bioresorbable Scaffolds Versus Drug-Eluting Stents in Chronic Total Occlusions

Background—There is little evidence regarding the efficacy and safety of bioresorbable scaffolds (BRS) for the percutaneous treatment of chronic total occlusions. Methods and Results—We performed a multicenter registry of consecutive chronic total occlusion patients treated with BRS (Absorb; Abbott Vascular) and second-generation drug-eluting stents (DES) at 5 institutions. Long-term target-vessel failure (a composite of cardiac death, target-vessel myocardial infarction, and ischemia-driven target-lesion revascularization) was the primary end point. Inverse probability of treatment weight–adjusted Cox regression was used to account for pretreatment differences between the 2 groups. A total of 537 patients (n=153 BRS; n=384 DES) were included. BRS patients were younger and had lower prevalence of comorbidities. Overall mean Japan-Chronic Total Occlusion (J-CTO) score was 1.43±1.16, with no differences between groups. Procedural success was achieved in 99.3% and 96.6% of BRS- and DES-treated patients, respectively (P=0.07). At a median follow-up of 703 days, there were no differences in target-vessel failure between BRS and DES (4.6% versus 7.7%; P=0.21). By adjusted Cox regression analysis, there were still no significant differences between BRS and DES (hazard ratio, 1.54; 95% confidence interval, 0.69–3.72; P=0.34). However, secondary analyses suggested a signal toward higher ischemia-driven target-lesion revascularization with BRS. Conclusions—Implantation of BRS versus second-generation DES in chronic total occlusion was associated with similar risk of target-vessel failure at long-term follow-up. However, a signal toward increased ischemia-driven target-lesion revascularization with BRS was observed. Large randomized studies should confirm these findings.

Current Risk of Contrast-Induced Acute Kidney Injury After Coronary Angiography and Intervention: A Reappraisal of the Literature

Contrast-induced acute kidney injury (CI-AKI) is the acute impairment of renal function further to the intravascular administration of iodinated contrast media, and occurs most frequently after coronary angiography, percutaneous coronary intervention, and contrast-enhanced computed tomography. CI-AKI has been associated with the development of acute renal failure, worsening of chronic kidney disease, requirement for dialysis, prolonged hospital stay, and higher mortality rates and health care costs. Recently, a number of studies suggested that contrast media exposure might not be the causative agent in the occurrence of acute kidney injury, particularly in stable patients who receive small to moderate amounts of contrast media. However, those who undergo coronary angiography and intervention are indeed subject to an increased hazard of CI-AKI, in view of a more significant contrast media exposure as well as the presence of concomitant risk factors. Solid randomized clinical trials are therefore required to identify preventative strategies to reduce the risk of CI-AKI and its complications in these patients.

Impact of left ventricular function on clinical outcomes of functional mitral regurgitation patients undergoing transcatheter mitral valve repair.

To evaluate the impact of baseline left ventricular (LV) function on the clinical outcomes of patients with functional mitral regurgitation (FMR) treated with MitraClip.

A novel maneuver to facilitate retrograde wire externalization during retrograde chronic total occlusion percutaneous coronary intervention

Although the retrograde approach has improved the success rate and procedural efficiency of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), it can still be challenging and time‐consuming. We introduce a novel technique that aims to facilitate the critical step of retrograde wire externalization during reverse controlled antegrade and retrograde tracking and dissection (CART), which we named DRAFT (Deflate, Retract and Advance into the Fenestration Technique).