Modeling Human Myocardium Exposure to Doxorubicin Defines the Risk of Heart Failure from Low-Dose Doxorubicin

The antitumor anthracycline, doxorubicin (DOX), can cause heart failure (HF) upon cumulative administration. Lowering the cumulative dose of DOX proved useful to minimize HF risk, and, yet, there is a growing concern that HF might occur after doses that were thought to be safe. Clinical trials that prospectively address such concerns are lacking. Because HF risk correlates with cardiac exposure to DOX, cumulative doses associated with HF risk were re-explored by modeling the accumulation of anthracycline pools in human myocardium. Ex vivo myocardial samples were used in vitro to simulate DOX rapid infusions. The accumulation of anthracycline pools was measured and incorporated into equations from which a risk versus dose curve was obtained. The experimental curve identified a 5% risk dose that was congruent with a previously reported clinical value (380 versus 400 mg/m², respectively); however, 1-2% risk occurred after lower doses than reported. Simulations of gain-of-function polymorphism of carbonyl reductase 3, which converts DOX to its poorly diffusible alcohol metabolite, doxorubicinol (DOXOL), expanded anthracycline pools and caused 5% or 1-2% risk doses to decrease to 330 or 180-230 mg DOX/m², respectively. These data show there is no safe dose of DOX. Diminishing cardiac exposure to circulating DOX may represent a cardioprotective strategy. We show that DOX slow infusions or liposomal DOX, which reduce cardiac exposure to DOX, caused formation of smaller anthracycline pools, did not generate DOXOL, increased the 5% risk dose to 750-800 mg/m², and prevented HF risk aggravation by carbonyl reductase polymorphism.

Pulmonary autograft in aortic position: is everything known?

The Ross operation provides several advantages compared to other valve substitutes to manage aortic valve disease, such as growth potential, excellent hemodynamics, freedom from oral anticoagulation and hemolysis, and better durability. However, progressive dilatation of the pulmonary autografts after Ross operation reflects the inadequate remodeling of the native pulmonary root in the systemic circulation, which results in impaired adaptability to systemic pressure and risk of reoperation after the first decade. A recently published article showed that remodeling increased wall thickness and decreased stiffness in the failed specimens after Ross operation, and the increased compliance might play a key role in determining the progressive long-term autograft root dilatation. Late dilatation can be counteracted by an external barrier which prevents failure. Therefore, an inclusion cylinder technique with a native aorta or a synthetic external support, such as Dacron, might stabilize the autograft root and improve long-term outcomes. In this article, we offer a prospective about the importance of biomechanical features in future developments of the Ross operation. Pre-clinical and clinical evaluations of the biomechanical properties of these reinforced pulmonary autografts might shed new light on the current debate about the long-term fate of the pulmonary autograft after Ross procedure.

Ischemic mitral valve prolapse

Ischemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third among the patients undergoing surgery for ischemic mitral regurgitation (IMR). IMP is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. IMP is not only a disorder of valvular function, but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension and a correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localization of prolapse, anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient's outcomes. This review will summarize our current understanding of the pathophysiology and clinical evidence on IMP with a particular focus on the surgical treatment.

Basic and Clinical Research Against Advanced Glycation End Products (AGEs): New Compounds to Tackle Cardiovascular Disease and Diabetic Complications

Diabetes is a major risk factor for cardiovascular disease, and recent advances in research indicate that a detailed understanding of the pathophysiology of its effects is mandatory to reduce diabetes-related mortality and morbidity. Advanced Glycation End Products (AGEs) play a central role in the genesis and progression of complications of both type 1 and type 2 diabetes mellitus, and have been found to be important even in non-diabetic patients as a marker of cardiovascular disease. AGEs have a profound impact on patient's prognosis regardless of the glycemic control, and therefore pharmacologic approaches against AGEs accumulation have been proposed over the years to treat cardiovascular diseases, parallel to a more detailed understanding of AGEs pathophysiology. Compounds with anti-AGEs effects are currently under investigation in both pre-clinical and clinical scenarios, and many of the drugs previously used to treat specific diseases have been found to have AGE-inhibitory effects. Some products are still in "bench evaluation", whereas others have been already investigated in clinical trials with conflicting evidences. This review aims at summarizing the mechanisms of AGEs formation and accumulation, and the most relevant issues in pre-clinical and clinical experiences in anti-AGEs treatment in cardiovascular research.

Is subvalvular repair worthwhile in severe ischemic mitral regurgitation? Subanalysis of the Papillary Muscle Approximation trial

OBJECTIVE

The symmetry of mitral valve tethering and regional left ventricle wall dysfunction are reported to play a fundamental role in the outcomes and long-term durability of surgical repair in ischemic mitral regurgitation (IMR). We recently demonstrated in a randomized clinical trial (the Papillary Muscle Approximation trial) the superiority of papillary muscle approximation (PMA) in combination with standard restrictive annuloplasty (RA) in severe IMR over annuloplasty alone in terms of adverse left ventricular remodeling and mitral regurgitation (MR) recurrence. This approach, however, failed to produce a survival advantage and was still plagued by a high incidence of reoperation. We therefore performed a subanalysis of the PMA trial on the basis of preoperative parameters to elucidate the value of subvalvular surgery in certain subcategories of patients with the aim of creating a decisional algorithm on the best operative strategy.

METHODS

We performed a subanalysis of PMA trial, evaluating 96 patients with severe IMR and eligible for myocardial revascularization randomized to PMA + RA (n = 48) versus RA alone (n = 48) in association with coronary artery bypass grafting. Endpoints included left ventricular remodeling, MR recurrence, overall mortality, reoperation, and a composite cardiac endpoint (cardiac death, stroke, reintervention, hospitalization for heart failure, or New York Heart Association class worsening). Stratification variables were preoperative symmetry of mitral valve tethering and regional wall motion abnormality.

RESULTS

PMA improved ventricular remodeling and recurrence of MR in both preoperative symmetric and asymmetric tethering and in case of inferior wall dyskinesia but did not produce an additional benefit in anterolateral wall dysfunction.

CONCLUSIONS

Preoperative symmetric and asymmetric tethering and isolated inferior wall dyskinesia are an indication for subvalvular apparatus surgery in IMR.

Is it time to change how we think about incomplete coronary revascularization?

The optimal degree of revascularization for patients with chronic multivessel coronary artery disease remains an unsolved issue. Intuitively, complete revascularization decreases cardiovascular events and improves outcomes compared to incomplete procedures, but in recent years the concept of incomplete revascularization moved from a sub-optimal or a defective treatment towards the most appropriate revascularization technique in some categories of patients. A reasonable level of incomplete anatomic revascularization has been shown to be safe and achievable with both percutaneous (PCI) and surgical procedures (CABG), despite with different long-term outcomes. What are the mechanisms underlying the clinical benefits of an incomplete revascularization and what are the factors explaining the discrepancy in the long-term clinical outcomes between the two modes of revascularization PCI and CABG? The biological consequences of coronary reperfusion might provide valuable hints in this context and at the same time cast new light on the way we think about incomplete revascularization.

Alteration in Collagen and Elastin Content in Varicose Veins

The nature and distribution of venous disease surrounding the development of varicose veins is controversial. Collagen and elastin are important components of the vein walls that affect their function. Collagen provides tensile strength, and elastin provides tissue elasticity

The amount of collagen and elastin was studied biochemically and histologically in two groups of human normal and varicose veins. The collagen content was higher in both dilatated and morphologically normal segments of varicose veins when compared with normal veins, whereas the elastin content was markedly decreased only in the dilatated segments of varicose veins. The ratio of thick to thin collagen fibers was almost invariable. These findings were consistent with the morphologic fibrosis that has regularly been described in varicose veins and emphasize the important role of elastin in providing the retractive force that opposes the development of dilatation and tortuosity of the vein wall.

Side-Branch of Internal Mammary Artery Bypass Graft Causing Coronary Steal

A case of coronary steal syndrome caused by a large unligated branch of the left internal mammary artery in a patient who had undergone myocardial revascularization is described. The presence of recurrent angina, a positive exercise stress test, and repeat angiography showing a lateral branch of the mammary artery led to a diagnosis of the coronary steal phenomenon. Surgical ligation of the branch was performed and the patient became symptom-free with a negative exercise stress test.

Primary Chylopericardium in a Heroin Addict

We describe a case of primary chylopericardium following acute Staphylococcus aureus endocarditis in a 33-year-old female heroin addict. The patient underwent surgical ligation of the thoracic duct after a low-fat diet failed to control the fluid accumulation. Three months postoperatively, the patient was in a good general condition and no pericardial effusion was observed.

Unconventional location for a cardiac lipoma: The anterior papillary muscle

Primary cardiac tumors are uncommon, and lipoma is the second most frequent benign type after myxoma. The treatment of choice is surgery, with the complete excision of the mass. Nevertheless, in the absence of symptoms and clinical signs the indication for surgery is less defined, and close follow up may be recommended. In the case we are going to report the patient was followed by periodical clinical and echographic examination, always reconsidering the possibility of treatment. <Learning objective: Cardiac lipoma is a tumor with different possible locations in the cardiac tissue and with different possible clinical patterns; in the presence of a cardiac lipoma the treatment of choice is surgery. The presence of a cardiac mass suggests investigating it with a high-resolution image examination, and to strictly follow the patient over time.>.

Hybrid Coronary Revascularization: An Attractive Alternative Between Actual Results and Future Trends

Optimal revascularization strategy in patients with multi-vessel coronary artery disease remains a matter of debate, with advantages and disadvantages in both surgical and percutaneous procedures. A combined approach to achieve coronary revascularization, termed "hybrid coronary revascularization" (HCR), has been recently introduced in clinical practice. HCR is defined as a scheduled combination of surgical left internal mammary artery to left anterior descending (LIMA-LAD) grafting and percutaneous treatment of at least one non-LAD coronary arteries, with both procedures planned and performed within a defined time limit. HCR is indicated in case of both proximal LAD disease eligible to surgical LIMA-LAD grafting and non-LAD disease amenable to percutaneous procedures. Reviews and metanalysis of the literature showed that HCR is non-inferior to conventional surgical myocardial revascularization, and in case of high-risk patients, HCR can be the ideal option. However, the various technical approaches and time-related steps need to be further evaluated. Present and future research in interventional cardiology and cardiac surgery will turn into parallel improvements in HCR procedures. Surgical revascularization with off-pump techniques and minimally-invasive approaches, scoring systems such as SYNTAX II, tools evaluating the hemodynamic significance of atherosclerotic plaques with physiology-based approaches such as fractional flow reserve and instantaneous wave-free ratio, newer generation drug eluting stents, newer antiplatelet agents, and therapies might improve indications and clinical outcomes after HCR procedures. This article reviews the current literature on HCR and aims to provide an overview about future developments.

Preliminary In Vivo Evaluation of a Hybrid Armored Vascular Graft Combining Electrospinning and Additive Manufacturing Techniques

In this study, we tested in vivo effectiveness of a previously developed poly-l-lactide/poly-ε-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings.

Effect of Preoperative Aspirin Replacement With Enoxaparin in Patients Undergoing Primary Isolated On-Pump Coronary Artery Bypass Grafting

Management of preoperative antiplatelet therapy in coronary artery bypass grafting (CABG) is variable among surgeons: guidelines collide with prejudices because replacement of aspirin with low-molecular-weight heparin is still performed because of a presumed minor bleeding risk. This study aims to analyze postoperative bleedings and complications in patients scheduled for elective primary isolated on-pump CABG, depending on preoperative aspirin treatment or its replacement with enoxaparin. In this cohort study, we propensity score matched 200 patients in whom aspirin was stopped at least 5 days before CABG and replaced with enoxaparin and 200 patients who continued aspirin therapy until the day before surgery. Postoperative bleedings and complications were monitored during hospitalization. Among patients who continued aspirin treatment, mean overall bleeding was 701.0 ± 334.6 ml, whereas in the matched enoxaparin group, it was significantly greater (882.6 ± 64.6 ml, p value <0.001); this was associated with reduced postoperative complications, lower values of postoperative C-reactive protein in aspirin takers, and a presumed protective effect for statins. After propensity score adjustment, aspirin treatment carried a protective effect against major postoperative bleeding (odds ratio 0.312, p = 0.001). In conclusion, postoperative bleeding is reduced in patients who continued aspirin, likely due to a reduction in postoperative inflammation. The practice of empirically discontinuing aspirin and replacing it with enoxaparin before CABG should be abandoned. Patients with coronary artery disease referred to CABG should continue antiplatelet medications until the surgical procedure. Those results might be extended to patients under oral anticoagulant therapy requiring CABG.

Redox proteomic analysis of serum from aortic anerurysm patients: insights on oxidation of specific protein target

Oxidative stress is undoubtedly one of the main players in abdominal aortic aneurysm (AAA) pathophysiology.

Predictive factors of long-term results following valve repair in ischemic mitral valve prolapse

BACKGROUND

In patients with ischemic mitral regurgitation, leaflet prolapse requires an accurate evaluation since surgical approach depends on valvular and subvalvular characteristics. This study aims to describe a cohort of patients over a long-term follow up, analyzing survival, reoperation and predictive factors of surgical outcomes.

METHODS AND RESULTS

From March 1994 to June 2011, 75 patients with ischemic mitral regurgitation and leaflet prolapse underwent surgical myocardial revascularization and mitral valve repair (90.7%) or replacement (9.3%). Our cohort was followed up until April 2015, with a mean follow up of 7 ± 3 years. Cardiac-related deaths occurred in 26 patients, with a mean survival of 114.2 months, including eight patients with in-hospital mortality. Reoperation was performed in 14 patients, due to valve repair failure. Twenty-six patients experienced moderate-to-severe mitral regurgitation. A preoperative LVEDD > 62 mm, LVESD > 52 mm, previous anteroseptal myocardial infarction, diffuse coronary artery disease, papillary anatomy type 1, partial rupture of the papillary muscle, A1-A2 scallop prolapse and postoperative mitral valve configuration (tenting area, tenting height, alfa-1 angle and alfa-2 angle) were identified as independent predictors of poor outcome. An index quantifying the stress on the annulus imparted by annuloplasty was elaborated and predicted endpoints.

CONCLUSION

Leaflet prolapse is an important entity in patients with ischemic mitral regurgitation, and its pathogenic mechanism mostly relies on papillary muscle lesion or elongation. Perioperative parameters describing geometric features of left ventricle, valvular and subvalvular components should be considered to provide a tailored approach for mitral valve repair, or to opt for immediate replacement in case of unfavorable geometry.

Double row of overlapping sutures for downsizing annuloplasty decreases the risk of residual regurgitation in ischaemic mitral valve repair

OBJECTIVES

The aim of this study was to evaluate a novel insertion technique of the prosthetic ring that would further magnify the degree of annulus narrowing, thereby reducing the potential for a residual leak in ischaemic mitral valve repair.

METHODS

Thirty-six patients with ischaemic mitral regurgitation (MR) were randomly assigned into two groups. In 18 patients, the prosthetic ring was inserted in the conventional manner with a single row of sutures (control group). In the remaining 18 patients, the ring was attached using a double row of sutures tied both on the inner and on the outer part of the sewing cuff. Both groups had similar preoperative clinical and echocardiographic characteristics with severe leaflet tethering: mean tenting area >2.5 cm(2), mean anterior leaflet angle >25° and posterior leaflet angle >45°. The mean prosthetic ring sizes inserted in both groups were identical (mean: 27.3 mm).

RESULTS

At 12 months, there was no clinical event except for 1 rehospitalization in the control group. The mean mitral regurgitation grade was higher in the control group than in the group with the double row of sutures at 1.6 ± 0.9 vs 0.7 ± 0.3 (P = 0.0003). Annulus diameter reduction was less pronounced in the control group when compared with the group with the double row of sutures, both in the parasternal long-axis: 29.3 ± 3 vs 26.3 ± 3 mm (P = 0.0003) and in apical four-chamber views: 31 ± 3 vs 28 ± 2 mm (P = 0.003). Leaflet tethering indices were greater in the control group than in the group with the double row of sutures: tenting area: 1.42 ± 0.3 vs 1.1 ± 0.5 cm(2) (P = 0.002), anterior leaflet angle: 33 ± 3° vs 28 ± 5° (P = 0.0009) and posterior leaflet angle: 110 ± 13° vs 80 ± 11° (P = 0.0001). Left ventricular function parameters were not statistically different among the two groups.

CONCLUSION

A double row of overlapping sutures for attaching the prosthetic ring in downsizing annuloplasty is more efficient in narrowing the mitral annulus than the conventional technique in ischaemic mitral repair. Even in high-risk patients whose leaflets were severely tethered on echocardiography, it almost eliminated the risk of MR recurrence in this study.

Pharmacologic Approaches Against Advanced Glycation End Products (AGEs) in Diabetic Cardiovascular Disease

Context:

Advanced Glycation End-Products (AGEs) are signaling proteins associated to several vascular and neurological complications in diabetic and non-diabetic patients. AGEs proved to be a marker of negative outcome in both diabetes management and surgical procedures in these patients. The reported role of AGEs prompted the development of pharmacological inhibitors of their effects, giving rise to a number of both preclinical and clinical studies. Clinical trials with anti-AGEs drugs have been gradually developed and this review aimed to summarize most relevant reports.

Evidence Acquisition:

Evidence acquisition process was performed using PubMed and ClinicalTrials.gov with manually checked articles.

Results:

Pharmacological approaches in humans include aminoguanidine, pyridoxamine, benfotiamine, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, statin, ALT-711 (alagebrium) and thiazolidinediones. The most recent promising anti-AGEs agents are statins, alagebrium and thiazolidinediones. The role of AGEs in disease and new compounds interfering with their effects are currently under investigation in preclinical settings and these newer anti-AGEs drugs would undergo clinical evaluation in the next years. Compounds with anti-AGEs activity but still not available for clinical scenarios are ALT-946, OPB-9195, tenilsetam, LR-90, TM2002, sRAGE and PEDF.

Conclusions:

Despite most studies confirm the efficacy of these pharmacological approaches, other reports produced conflicting evidences; in almost any case, these drugs were well tolerated. At present, AGEs measurement has still not taken a precise role in clinical practice, but its relevance as a marker of disease has been widely shown; therefore, it is important for clinicians to understand the value of new cardiovascular risk factors. Findings from the current and future clinical trials may help in determining the role of AGEs and the benefits of anti-AGEs treatment in cardiovascular disease.

Successful Valve Prolapse Repair for Ischemic Mitral Regurgitation: Combined Papillary Muscle Approximation and Mitral Chordae System Replacement

Mitral valve prolapse occurs in 33.6% of patients undergoing surgery for ischemic mitral regurgitation (IMR). In the context of IMR, reparative strategy cannot disregard the underlying mechanism of pathogenesis and the progressive geometric alteration affecting left ventricle and papillary muscles. We present a case of extended mitral prolapse of the posteromedial commissure and A3 concomitant to chordal injury after inferior myocardial infarction. We propose a combined sequential approach including papillary muscle approximation and a mitral chordae system replacement.