Mitral balloon valvuloplasty

Although the prevalence of rheumatic fever has greatly decreased in Western countries, mitral stenosis (MS) still results in significant morbidity and mortality worldwide. The treatment of MS has been revolutionized since the development of balloon mitral valvuloplasty (BMV). Until the first publication by Inoue in 1984, surgery was the only treatment for patients with mitral stenosis. Since then, the technique has evolved considerably. A large number of patients with varied conditions have now been treated worldwide, enabling us to assess the efficacy and risk of the technique, and long-term results make us better able to select the most appropriate candidates for treatment using this method.

Laser

The first medical application of laser was reported by Dr Leon Goldman who, in 1962, reported the use of ruby and carbon dioxide (CO2) lasers in dermatology. In cardiovascular disease, early laser use was confined to cadaver vessels, animal models, and arteries located in freshly amputated limbs, until eventually work progressed to the use of laser energy to salvage an ischaemic limb in 1984. The concept of using laser to remove atherosclerotic material in coronary arteries developed as an alternative strategy to simply modifying the shape of an obstructed lumen as occurs with simple balloon angioplasty. Expectations grew that this new biomedical technology may overcome the low success rate and high complication rate of lesions considered non-ideal for balloon angioplasty. However, initial successful reports could not be replicated. Furthermore, underdeveloped catheter technology and limited appreciation of laser/tissue interactions meant that a cure for restenosis was not in fact discovered and laser coronary angioplasty became isolated to only a few centres in the world. However, more recently with advancement in both catheter technology and technique, excimer coronary laser angioplasty (ELCA) has been rediscovered for use in specific subsets of percutaneous coronary interventions (PCIs). This chapter outlines the basic principles of ELCA and important practical aspects for using the device in contemporary PCI. A discussion of the current indications for clinical use follows and these are highlighted by clinical case examples.

Rotational atherectomy

Since 1979, plain old balloon angioplasty (POBA) has provided relief of angina for many patients. Recurrent symptoms due to restenosis diminished with bare-metal stent and, more recently, drug-eluting technology. A limitation to achieving good results with POBA and stenting is calcification within the artery which not only can prevent passage of balloons and stents into a lesion but also may prevent adequate lumen expansion. Rotational atherectomy or rotablation (RA) can treat highly resistant calcified plaque within coronary arteries to allow adequate vessel expansion and ensure optimal stent deployment. The concept of using a high-speed diamond-tipped drill spinning at 150 000rpm driven by compressed air to clear an artery that is 3mm in diameter is challenging, yet this technique has been available for use in coronary arteries since 1989 when M.E. Bertrand (Lille, France) and R. Erbel (Essen, Germany) first used it in humans.

Stent thrombosis

Over the past three decades, new strategies have rapidly evolved to achieve coronary reperfusion of ischaemic myocardium in patients with coronary artery disease (CAD). Studies comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) have shown that the long-term rates of death and/or myocardial infarction (MI) are substantially the same, justifying the increasing and widespread use of PCI. PCI is the dominant reperfusion therapy for such patients with the ratio of numbers of PCIs undertaken to CABG performed being 4:1 in the United Kingdom and up to 8:1 in other parts of Europe. A recurrent issue during the evolution of PCI has been the difference between PCI and CABG in the percentage of patients requiring a repeat procedure (reintervention). To date, the need of reintervention has been less with CABG and this is due to the development of in-stent restenosis that occurs after PCI. Restenosis is the re-narrowing of the vessel, which requires a repeat procedure. The rate of restenosis with early balloon angioplasty has been high. The implantation of bare metal stents (BMS) and then drug-eluting stents (DES) has reduced significantly the incidence of restenosis. While such improved overall clinical outcomes with DES has supported the use of these in preference to BMS, another long-term complication has somewhat tempered the enthusiasm for their use: the possibility that implantation of DES would result in an excess of occlusive stent thrombosis (ST). This chapter will analyse the data on the incidence, causes, and clinical consequences of ST, and will outline the ongoing and future preventive and therapeutic initiatives. Finally, the risk/benefit of DES will be addressed.

Optimal medical therapy in percutaneous coronary intervention patients: statins and ACE inhibitors as disease-modifying agents

The majority of this textbook is concerned with the indications for, and applications of, the numerous techniques that interventional cardiologists have at their disposal to assess and treat significant coronary stenoses. However, it is well recognized that atherosclerosis is far from being a discrete pathological process, such that by the time a person presents with clinically apparent coronary artery disease (CAD), they will often have widespread atheroma throughout their coronary tree. Combined with the reproducible observation that the majority of acute coronary syndromes arise from lesions that were not previously flow-limiting, much research effort has been directed at identifying treatment strategies that will favourably modify all of the patient’s atherosclerotic burden, not just that which can be targeted by percutaneous or surgical revascularization. In this chapter, we focus on the rationale and evidence base supporting the use of statins and renin–angiotensin–aldosterone system (RAAS) inhibition in patients with CAD.

Percutaneous coronary intervention for unprotected and protected left main stem disease

Significant unprotected left main coronary artery (ULMCA) disease occurs in 5–7% of patients undergoing coronary angiography (and patients with ULMCA disease treated medically have a 3-year mortality rate of 50%. Several studies have shown a significant benefit following treatment of left main (LM) stenosis with coronary bypass grafting compared with medical treatment. Until recently coronary bypass grafting has been the gold standard therapy for LM disease. However, advances in percutaneous intervention techniques and stent technology have allowed re-evaluation of the role of percutaneous coronary intervention (PCI) for LM disease. Recent studies have focused on the safety and efficacy of stenting the left main coronary artery (LMCA) to determine if it does provide a true alternative to coronary artery bypass grafting (CABG). So should we stent the LM?

Routine management after percutaneous coronary intervention

Following a technically successful procedure, it is the post-procedural care of the patient that will often dictate both short- and long-term outcomes. Post-procedural care involves close monitoring of the patient for early complications, which may be secondary to the procedure itself or the presenting complaint. Immediate complications following percutaneous coronary intervention (PCI) may occur due to bleeding, most commonly at the access site, or due to early cardiac complications, often related to technical issues during the procedure. Non-cardiac complications, such as the development of contrast nephropathy, will become apparent in the hours or days following the initial procedure. Prompt and accurate identification of post-procedural complications is essential if they are to be managed effectively, and identification of the ‘at risk’ patient may also facilitate early identification of problems when they do occur. Complication rates are higher in patients with acute coronary syndromes, often exacerbated by aggressive antithrombotic regimens, and also in older patients with comorbid conditions. The type of care and length of stay will also vary according to the clinical context and needs to be carefully considered once the PCI has been performed. Following discharge, the longer-term management of residual coronary disease and recurrent ischaemia along with appropriate secondary prevention may all affect longer-term outcome. This chapter will examine the issues surrounding the immediate and longer-term care of the patient following PCI.

Carotid artery stenting

Stroke is the third leading cause of death in the developed world. Internal carotid artery (ICA) stenosis is a major correctable cause of ischaemic stroke, the risk being related to the degree of stenosis and the presence of recent symptoms. Carotid endarterectomy (CEA) has become the preferred method of treatment for patients with asymptomatic or symptomatic high-grade ICA stenosis, supplanting medical therapy alone. In coronary disease, the increasing use of percutaneous coronary intervention (PCI) has reduced the need for coronary artery bypass surgery (CABG). Unlike coronary stenting, where immediate relief of anginal symptoms can justify the procedure, carotid intervention is not usually done for haemodynamic or flow indications, but to reduce future emboli. For significant (greater than 50% angiographic) ICA stenosis, carotid artery stenting (CAS) is a reasonable alternative to CEA, but its true place is as yet undecided, and awaits the conclusion of several ongoing randomized trials.

Transcatheter aortic valve replacement

Aortic stenosis (AS) is the most common valvular heart disease for which patients undergo valve replacement. Although the condition may develop in mid-life in association with a congenitally bicuspid valve, AS is for the most part a disease of the elderly, as demonstrated by a recent community-based study in the United States which reported a prevalence in those older than 75 years of age of 4.6%. Medically treated severe symptomatic AS has been associated with predictable clinical deterioration and a poor survival, reportedly averaging 2–3 years after the onset of symptoms.

Percutaneous device closure of atrial septal defect and patent foramen ovale

Structural heart disease interventions look set to form an increasing proportion of the interventional cardiologist’s workload. Device closure of atrial septal connections, both patent foramen ovale (PFO) and atrial septal defect (ASD), are the most commonly performed adult structural interventional procedure in the United Kingdom, with 793 PFO and 573 ASD closure procedures performed in adults in 2007. Device closure of ASDs and PFOs are elegant procedures which combine technical and imaging skills with a detailed understanding of cardiac anatomy. More importantly, they also provide tangible clinical benefits to patients.