Since the description of left main coronary artery disease (LMCA),1 its prognostic importance has been shown in different scenarios.2 Observational3 and randomized studies4 have confirmed the benefits of surgical revascularization in these patients. The percutaneous approach5,6 may be an option in highly symptomatic inoperable patients. However, angiographic evaluation of LMCA segments is sometimes difficult to interpret.7 In some patients, intermediate lesions of the LMCA coexist with significant stenoses in other arteries; furthermore, some patients present equivocal symptons accompanying non-diagnostic results of different tests for ischemia in the presence of moderate obstructions of the LMCA, making it difficult to discern the true meaning of these obstructions and, thus, the ideal therapeutic approach.

It has long been recognized that evaluation of the severity of stenoses in the left main is more difficult than at most other sites in the coronary tree, although much of supporting data dates from the time when patients underwent angiography in rotating cradles. Nonetheless, vessel overlap and eccentric stenoses still plague angiographic assessment of lesions at this prognostically important site.
But the severity of stenosis is a poor harbinger of events. Granted, randomized trials performed in the distant past suggested bypass surgery is superior to medical therapy alone for patients with > 50% lesions at this site. Their relevance, in an era of aggressive statin therapy, soon to be available agents that dramatically increase HDL and when bypass surgery is not the only means technically available for revascularization is questionable, and only of modest assistance to the patient and treating physician.

Over the last decade, coronary stent implantation has gradually become the choice treatment of choice in percutaneous coronary intervention (PCI).1,2 The enhanced safety of coronary interventions, the lower complication rate, the better immediate angiographic and functional results and especially the lower restenosis rate compared to balloon angioplasty have won the battle with other interventional treatment modalities in all but a few types of lesions.3–9 Today, a huge number of different models and makes of coronary stents are available. In the early years of the 21st century all attention is focused on the new development of drug eluting stents, promising the ultimate solution of the restenosis problem.10,11

In the paper by Lee and colleagues (see pages 406–409), the authors seek to establish whether stenting after coronary rotational atherectomy (RA) for “complex lesions” offers any advantage over rotational atherectomy plus adjunctive PTCA alone.1 It presents an interesting, albeit retrospective, comparison of outcomes obtained by patients undergoing these two different treatment modalities.

Despite the evolution of interventional techniques and operator experience, percutaneous revascularization of complex coronary lesions (i.e., calcified and long lesions) remains challenging because of lower procedural success rates and higher restenosis rates.1–4 Intravascular ultrasound study has demonstrated that increased coronary calcium is an important determinant of decreased wall compliance,5 and leads to a high incidence of dissections when these lesions are treated with balloon angioplasty. If coronary stenting is performed in this setting, an incomplete and asymmetric stent expansion occurs in up to 50% of cases.6 In addition to a low rate of procedural success and a high rate of late restenosis, long coronary lesions also usually have other clinical or angiographic features, including diabetes mellitus, multi-vessel disease, more calcific lesions and even unsuitable anatomy for coronary bypass surgery.

Stent placement in coronary arteries >= 3.0 mm in diameter has been irrefutably proven to be superior to conventional balloon angioplasty (PTCA) in reducing the risk of restenosis and major adverse cardiac events.1–4 Subsequent improvements in stenting technique and antithrombotic regimen have dramatically reduced the incidence of stent thrombosis.5–9 These favorable outcomes in concert have resulted in an exponential rise in the volume of stent-related procedures and have extensively broadened the indications for stenting to encompass non-STRESS/BENESTENT lesions, including, among others, lesions in small coronary arteries (< 3.0 mm in diameter). It is estimated that 30–50% of all percutaneous coronary interventions involve small vessels.

Since the inception of coronary angioplasty, small vessel disease has been a particularly challenging subset to treat with percutaneous interventional therapies. Historically small vessel intervention has been complicated by a higher incidence of significant vessel dissection, acute vessel closure, myocardial infarction and emergent coronary bypass grafting.1,2 Furthermore, these lesions are frequently technically difficult. Their often non-compliant and calcified character, frequent tortuous nature, and predominant distal location impair device delivery and expansion. Along with poorer acute outcomes, these subsets are plagued by high restenosis rates, often necessitating repeat intervention or bypass surgery.3 Despite the challenges and complexities inherent to small-vessel intervention, the problem is common, with 30 to 40% of all interventions involving small coronary arteries.4,5

Minimally invasive direct coronary artery bypass (MIDCAB) has been successfully used to treat isolated lesions of the left anterior descending (LAD) artery by operating on the beating heart without cardiopulmonary bypass (CPB) with excellent medium-term results.1 MIDCAB involves open harvesting of the left internal thoracic artery (LITA) through a small left anterior thoracotomy incision or lower hemisternotomy incision (Figure 1). The LITA is then sewn directly to the LAD on the beating heart through this limited opening.

Coronary artery bypass grafting of the left anterior descending coronary artery (LAD) using internal mammary artery (LIMA) has been shown to be more effective than interventional treatment with respect to event-free survival and relief of ischemic symptoms.1,2 Internal mammary graft to LAD has a patency rate of more than 95% at 5 years.3 However, the disadvantages of conventional bypass surgery include neuro-cognitive impairment resulting from cerebral embolization of atherosclerotic plaque, air, fat and platelet aggregates, marked hemodynamic fluctuations, cerebral hyperthermia after the discontinuation of cardiopulmonary bypass and inflammatory and neurohumoral derangements associated with surgery.4,5 Cerebral complications are responsible for an increasing proportion of peri-operative deaths.6,7 Alternative forms of surgery which are minimally invasive are thus being investigated.

Invasive coronary procedures, such as rotational atherectomy and coronary artery bypass graft (CABG) stenting, are associated with vasoconstriction that sometimes results in increased morbidity or death. The “no-reflow” phenomenon, an adverse effect of cardiac catheterization, and transient perioperative hypertension are examples of vasoconstriction-related complications. Vasodilators such as injectable calcium channel blockers, sodium nitroprusside and adenosine are effective agents for the treatment of these complications. Nicardipine, a dihydropyridine calcium channel blocker, has several unique properties that make it an appealing treatment option for reversing vasoconstriction.