When the Complex Meets the High-Risk: Mechanical Cardiac Support Devices and Percutaneous Coronary Interventions in Severe Coronary Artery Disease

Coronary artery disease (CAD) remains a leading cause of mortality and morbidity worldwide. Few practice guidelines directly address the issue of revascularization in patients with CAD at higher risk of periprocedural complications. It remains a challenge to appropriately identify the subset of patients with CAD who will require short-term use of mechanical cardiocirculatory support devices (MCSDs) when high-risk (HR) percutaneous coronary intervention (PCI) is required. Issues of the complexity (coronary anatomy and high burden of comorbidities) and risk status (hemodynamic precarity or compromise) need to be considered when considering revascularization in patients. This review will focus on the evolving concept of protected PCI in patients with CAD, and how a balanced, integrated heart-team approach remains the path to optimal patient-centred care in the setting of HR-PCI supported with MCSD.     

Platelet Inhibition in Percutaneous Coronary Interventions

Abstract Mechanical disruption of atherosclerotic plaques at the time of percutaneous coronary intervention (PCI) is a potent stimulus for arterial thrombosis. Since platelets play a crucial role in the cascade of clot formation, platelet inhibition is an essential step for successful PCI. Aspirin remains the cornerstone of any antithrombotic regimen in the interventional setting. The addition of a thienopyridine is mandatory following stenting to prevent thrombosis of the device. Whenever possible, patients undergoing PCI should be pretreated with clopidogrel and the drug should be continued for up to 1 year. Glycoprotein IIb/IIIa antagonists should be administered in high-risk patients, such as those with acute coronary syndromes, diabetes, or complex coronary anatomy.     

Sex Differences in Percutaneous Coronary Interventions

Cardiovascular disease is the leading cause of mortality in women, and women have a higher cardiovascular mortality and morbidity associated with the treatment of cardiovascular disease compared to men. Percutaneous coronary intervention (PCI) is an important therapy for women with coronary artery disease particularly in acute coronary syndromes; however, only 33% of all PCIs are performed in women. The purpose of this review is to evaluate the evidence for PCI in women and demonstrate the unique aspects of therapy in regard to sex.     

Operator Volume and Outcomes in 12,988 Percutaneous Coronary Interventions

Objectives. We sought to determine whether there is a relation between operator volume and outcomes for percutaneous coronary interventions (PCIs).Background. A 1993 American College of Cardiology/American Heart Association task force stated that cardiologists should perform ≥75 procedures/year to maintain competency in PCIs; however, there were limited data available to support this statement.Methods. Data were collected from 1990 through 1993 on 12,988 PCIs (12,118 consecutive hospital admissions) performed by 31 cardiologists at two hospitals in New Hampshire and two in Maine and one hospital in Massachusetts supporting these procedures. Operators were categorized into terciles based on annualized volume of procedures. Univariate and multivariate regression analyses were used to control for case-mix. Successful outcomes included angiographic success (all lesions attempted dilated to <50% residual stenosis) and clinical success (at least one lesion dilated to <50% residual stenosis and no adverse outcomes). In-hospital adverse outcomes included coronary artery bypass graft surgery (CABG), myocardial infarction (MI) and death.Results. After adjustment for case-mix, higher angiographic (low, middle and high terciles: 84.7%, 86.1% and 90.3%, p-trend 0.006) and clinical success rates (85.8%, 88.0% and 90.7%, p-trend 0.025), with fewer referrals to CABG (4.54%, 3.75% and 2.49%, p-trend <0.001), were seen as operator volume increased. There was a trend toward higher MI rates for high volume operators (2.00%, 1.98% and 2.57%, p-trend 0.06); all terciles had similar in-hospital mortality rates (1.09%, 0.96% and 1.05%, p-trend 0.8).Conclusions. There is a significant relation between operator volume and outcomes in PCIs. Efforts should be directed toward understanding why high volume operators are more successful and encounter fewer adverse outcomes.     

Advances in Percutaneous Coronary Interventions for Elderly Patients

Coronary heart disease (CHD) is one of the leading causes of morbidity and the most common cause of death in older adults. Paradoxically, elderly patients tend to be systematically excluded from randomized-controlled cardiovascular trials, which complicates decision-making in this population. Management of CHD in the elderly is frequently more difficult in virtue of chronic comorbid conditions and aging-intrinsic dynamics. Despite these challenges, the number of elderly and very elderly patients undergoing percutaneous coronary interventions (PCI) is increasing. Elderly patients in many registries and large clinical series exhibit even a greater benefit from interventional procedures than younger patients, but they have a higher rate of overall complications. We present an overview of the current available evidence of PCI in older adults with stable and unstable CHD, including comparisons between drug-eluting and bare-metal stents, transfemoral and transradial access, and methods of revascularization. Adjuvant antiplatelet and antithrombotic therapies are also discussed.     

Bivalirudin in Percutaneous Coronary Interventions and Acute Coronary Syndromes: New Concepts, New Directions

Inhibition of thrombin and platelets during percutaneous coronary intervention (PCI), using a combination of unfractionated heparin and aspirin, is designed primarily to minimize the rare but devastating potential acute thrombotic complications of the procedure. Direct thrombin inhibitors, such as bivalirudin (formerly Hirulog, The Medicines Company, Cambridge, MA), offer specific theoretic advantages over unfractionated heparin as antithrombin therapy. This review focuses on the pharmacologic promise and the clinical performance of bivalirudin in PCI, and in the pharmacologic management of acute coronary syndromes. Clinical experience with bivalirudin in PCI preceded recent dramatic advances in mechanical interventional techniques and the emergence of novel potent platelet inhibitors. The role of bivalirudin and other direct thrombin inhibitors in the modern era of coronary intervention therefore requires further elucidation.     

Use of Fentanyl During Percutaneous Coronary Interventions: Safety and Drawbacks

Over the last years, fentanyl, a potent synthetic μ receptor–stimulating opioid, has become one of the most used drugs for both procedural analgesia and sedation in patients undergoing coronary angiography (CA) and/or percutaneous coronary intervention (PCI). However, few studies have been performed to evaluate the efficacy and the impact of this drug in patients with coronary artery disease (CAD) treated with PCI. Most of the previous studies have investigated the self-reported discomfort pain, demonstrating that patients premedicated with fentanyl generally reported a lower pain/discomfort when compared to placebo, benzodiazepines, or local anesthesia at the site of the artery cannulation, without significant variation in the hemodynamic response. The biochemical properties of fentanyl have been used to prevent the radial arterial spasm, which represents one of the major causes of the access site cross-over during PCI, experienced when radial artery cannulation has failed and successful access can be obtained only switching to an alternative arterial route, as the ulnar or the femoral artery. However, some unresolved problems, as fentanyl-induced hypothermia and delayed absorption of P2Y₁₂ inhibitors required further investigations.     

Reducing Radiation in Chronic Total Occlusion Percutaneous Coronary Interventions

The field of percutaneous intervention for chronic total occlusion (CTO) has enjoyed significant innovations in the recent years. Novel techniques and technologies have revolutionized the field and have resulted in considerably higher success rates even in patients with high anatomical complexity. Successful CTO recanalization is associated with significant clinical benefits, such as the improvement of angina and quality of life, reduced rates of surgical revascularization, improvement of left ventricular function and decreased mortality rates. However, complex CTO procedures often require prolonged x-ray exposure which have been associated with adverse long term outcomes.     

Modulating Thrombotic Potential in Catheter-Based Percutaneous Coronary and Peripheral Vascular Interventions

Thrombosis is an obligatory consequence of all percutaneous vascular interventions. Balloon angioplasty, intravascular stents and other devices routinely used to facilitate dilatation of critical vascular stenoses result in fracture of the intima and exposure of the thrombogenic subendothelium with initiation and perpetuation of platelet activation and aggregation. This not uncommonly results in thrombus formation that may lead to abrupt vessel closure, distal ischemia and tissue infarction, and target organ dysfunction. Fortunately, advances in our understanding of the mechanisms that underlie vascular thrombosis have led to advances in the use of adjunctive pharmacological agents that modulate this pathophysiological response and have led to important reductions in the incidence and severity of thrombotic complications of percutaneous transluminal interventions.     

Platelet and Thrombin Inhibitors as Adjuncts to Thrombolytic Therapy and Percutaneous Coronary Interventions: A Review

A large body of evidence supports the critical role of thrombus formation in the pathogenesis of acute MI as well as the early ischemic complications after percutaneous coronary interventions. Both platelets and the plasma proteins involved in fibrin formation are intimately involved in the thrombotic process. Recently, pharmacological agents that hinder fibrin formation and platelet activation or aggregation have been developed. These drugs are being tested in patients with acute MI, in conjunction with thrombolytic agents, and in patients undergoing percutaneous coronary interventions. So far, the antiplatelet agents appear very promising in the area of percutaneous coronary intervention. Information on their role in acute myocardial infarction is still too preliminary to draw conclusions. Results with antithrombin agents have been less promising. This article will briefly describe the mechanisms of thrombus formation, detail the mechanism of action of available antithrombotic pharmacological agents, and review recent clinical trials of these agents.     

Percutaneous Coronary Interventions in Facilities Without Cardiac Surgery on Site

Prior to the widespread adoption of intracoronary stent implantation, potential complications of percutaneous coronary intervention (PCI) necessitated the presence of backup cardiac surgery. However, as stent implantation has become the predominant form of PCI, the incidence of emergent cardiac surgery has declined exponentially. Despite this, current guidelines recommend against the performance of elective PCI at hospitals without on-site cardiac surgery and recommend that primary PCI for ST-segment elevation myocardial infarction (STEMI) might be considered at hospitals without backup cardiac surgery. These recommendations are based predominantly on two principles: (1) hospital volume for PCI is strongly associated with clinical outcomes, and (2) results from a large registry study, in which the authors reported a substantial increase in mortality among patients undergoing non-primary/rescue PCI at hospitals without backup cardiac surgery. Since that time, evidence from multiple studies has suggested that performance of PCI at hospitals without backup cardiac surgery is feasible, safe, and both clinically and cost effective. Among STEMI patients, in particular, performance of primary PCI at hospitals without on-site cardiac surgery reduces time to reperfusion and subsequent adverse cardiovascular events as well as likely reducing infarct size. In this review, we will examine the evidence surrounding the performance of PCI for stable and unstable coronary disease at hospitals without on-site backup cardiac surgery.