Does optical coherence tomography identify arterial healing after stenting? An in vivo comparison with histology, in a rabbit carotid model.

OBJECTIVE: To verify whether optical coherence tomography (OCT) can accurately monitor the occurrence of arterial healing after stenting. SETTING: Delayed stent endothelialisation may predispose to stent thrombosis. OCT is a high-resolution intravascular imaging technique that accurately identifies stent struts and arterial tissues. DESIGN AND INTERVENTIONS: Eight New Zealand white rabbits underwent the implantation of single bare metal stents (diameter 2-2.5 mm, length 8-13 mm) in the right common carotid artery through the external carotid artery. After a median of 11 days (range 2-28), the stented arteries were visualised by OCT, with images acquired at a pull-back speed of 0.5 mm/sec. The rabbits were then euthanised, vessels were formalin-fixed and finally processed for histopathology. RESULTS: We analysed 32 cross-sections from eight stented carotid arteries, for a total of 384 stent struts. OCT detected all of the stent struts in 30 of 32 cross-sections (93.7%), and correctly identified the presence/absence of tissue for every strut. Histological and OCT measurements of mean neointima thickness (0.135 (SD 0.079) mm and 0.145 (SD 0.085) mm, respectively, p = NS) were similar and closely related (r = 0.85, p<0.001). Neointima area progressively increased with longer time intervals from stent deployment to sacrifice; histological and OCT measurements were similar for each time interval. The intra-observer and interobserver reproducibility of OCT neointima measurements were excellent (R2 = 0.90 and 0.88, respectively). CONCLUSIONS: OCT is a promising means for monitoring stent strut coverage and vessel wall healing in vivo, the relevance of which will become even more significant with the increasing use of drug-eluting stents.

Mechanisms of nitrate tolerance: potential roles of folate.

More than 100 years since their introduction in cardiovascular therapy, nitrates continue to be widely used in ischaemic heart disease despite incomplete knowledge of their intimate mechanism of action. Particularly, the development of a progressive attenuation of their efficacy over prolonged use (tolerance) continues to be the subject of current investigation. Newer findings point to the role of increased intracellular oxidative stress as a mechanism for tolerance and to folic acid derivatives as pharmacologic means to attenuate its development. This paper reviews nitrate mechanism of action, the history of nitrate tolerance and newer findings related to the use of folate to prevent this phenomenon.

Age-dependence of risk factors for carotid stenosis: an observational study among candidates for coronary arteriography.

In order to identify subjects at higher risk for carotid stenosis and to provide insights into mechanisms of disease development at different age-intervals, a color duplex ultrasound of extracranial arteries was performed in 624 consecutive patients (mean age 62.9+/-10.7, 483 males) undergoing coronary angiography. Significant carotid atherosclerosis (> or =50% stenosis) was documented in 87 patients (14%): the disease was moderate (50/69% stenosis) in 51 patients (8%), severe (> or =70% stenosis) in 36 patients (6%). Age (P<0.0001), smoking (P<0.0001), diabetes (P=0.0002), renal dysfunction (P=0.0119) and hypertension (P=0.0202) were independent predictors of significant carotid atherosclerosis; age (P=0.0001), smoking (P=0.0009) and diabetes (P=0.0201) were independent predictors of severe disease. Among 262 candidates for cardiac surgery, significant carotid artery disease was identified in 57 cases (2.63 Relative Risk, 95% Confidence Intervals: 1.32/5.24). Correlation and regression tree analysis demonstrated that diabetes was associated with greater severity of carotid stenosis in younger patients and hypertension in older ones. In conclusion age is the primary determinant of carotid artery disease; diabetes and smoking accelerate progression of atherosclerosis in younger patients, hypertension and smoking in older ones. Among patients undergoing coronary angiography, carotid ultrasonography should be recommended in high risk subgroups of patients.

Percutaneous interventions on arterial conduits.

Because of the extensive use of arterial conduits for coronary surgery and the increased risk of repeat surgery in cases of graft failure, there is a growing interest in percutaneous interventions (PI) for patients with conduit dysfunction. PI on arterial conduits is a challenge for the interventional cardiologist, due to anatomic and functional characteristics of the graft. There are no large-scale multicenter or randomized studies focusing on PI of arterial conduits. Few single-center experiences are available, and all report short-term encouraging results and < 20% restenosis rates. Procedural failures are mainly due to graft tortuosity or length. Spasm is not rarely reported in muscular conduits. Stents are effective for the treatment of ostial disease and in bail-out cases, but should be cautiously used in anastomotic lesions. In patients with patent internal mammary artery, large pectoralis branches are sometimes considered responsible for steal phenomena, but flow diversion is usually trivial and embolization should be accomplished only after careful functional evaluations. PI can safely be performed on arterial grafts, with careful planning and knowledge of conduit pathophysiology.

[Carotid atherosclerosis in patients with suspected coronaropathy: the relationship to traditional risk factors in the 2 vascular areas]. / Aterosclerosi carotidea in pazienti con sospetta coronaropatia: relazione con i fattori di rischio tradizionali nei due distretti vascolari.

UNLABELLED: In order to evaluate the prevalence of carotid atherosclerosis (CA) in patients with coronary artery disease (CAD) and to identify the differential role of traditional risk factors, we analyzed data concerning 290 patients aged 61.9 +/- 10.8 years who underwent color duplex ultrasound of extracranial arteries before coronary angiography. Significant CA (stenosis > or = 50% in at least one extracranial artery) was disclosed in 44 patients (15%); significant CAD (stenosis > or = 70% at least in a major epicardial vessel) was documented in 238 patients (82%). Age and smoking were significantly associated with both CAD (respectively, p = 0.034 and p = 0.050) and CA (respectively, p = 0.000 and p = 0.000), but a stronger correlation was documented with CA (r = 0.325 vs r = 0.125 for age; r = 0.218 vs r = 0.114 for smoking). Diabetes (p = 0.031) and male gender (p = 0.016) were significantly associated with CAD, and hypertension (p = 0.029) with CA. CONCLUSIONS: Traditional risk factors play different roles in the pathogenesis of atherosclerotic disease of carotid and coronary circulation. Color duplex evaluation of the carotid arteries can be useful in high-risk patients, particularly if candidates for coronary surgery.

Surgical treatment of dilated cardiomyopathy with conventional techniques.

OBJECTIVE: We review our surgical experience using different conventional surgical techniques in the surgical treatment of the dilated cardiomyopathy (DCMP) in non-transplant eligible patients. METHODS: In this series we included patients who fit the following criteria: ejection fraction < 35%; end diastolic volume > or = 110 ml/m2; enlargement of the base of the heart (maximal mitral diameter > or = 22 mm/m2) with functional mitral regurgitation; mitral surgery to be performed in every case. Moreover, two groups were considered. (A) Normal or moderately impaired right ventricular function; PAP < 45 mmHg; elective or semielective surgery. (B) Severely impaired right ventricular function; PAP > or = 45 mmHg; severe organ failure; dependency on IABP and/or inotropes; need of ICU stay. From January 1990 to September 1998, 66 patients underwent isolated mitral valve surgery (n = 30); in the remaining 36 the Batista operation (n = 21) or exclusion of akinetic areas (n = 15) were associated. The etiology was ischemic in 42, idiopathic in 23 and post-valvular in one. RESULTS: When isolated mitral valve surgery was performed, early mortality in group A (n = 22) was 0, in group B (n = 8) 50%. Overall 5-year survival was 70.0 +/- 8.4. in group A 81.8 +/- 8.2, and in group B 37.5 +/- 17.1. When the Batista operation was performed, early mortality in group A (n = 13) was 23.1%, in group B (n = 8) 75%. Overall 2-year survival was 42.9 +/- 10.8 in group A 61.5 +/- 13.5 and in group B 25.0 +/- 15.3. When akinetic areas were excluded, early mortality in group A (n = 11) was 18.2% and in group B (n = 4) 100%. Overall 1-year survival was 53.3 +/- 12.9, in group A 72.7 +/- 13.4. CONCLUSION: Group A patients have better results in every cohort of patients considered. Even if patients selection seems to be the most important variable for early mortality and late survival, isolated mitral valve surgery, when feasible, provides the best early and late results.

[Single coronary artery with a right origin: angiography identification of the R-II subgroup]. / L'arteria coronaria singola di tipo destro: identificazione angiografica del sottogruppo R-II.

This case report illustrates the clinical and angiographic findings of 2 patients undergoing coronary angiography for ischemic heart disease and with the unexpected presence of anomalous origin of the left coronary artery from the right aortic sinus. The angiographic classification of the different subgroups of single coronary artery is reviewed and the 2 cases are identified as type R-II with septal and anterior course of the left main stem.

Multiple arterial conduits without cardiopulmonary bypass: early angiographic results.

BACKGROUND: Lack of angiographic results and technical difficulty in grafting the vessels in the lateral and posterior walls have reduced interest in myocardial revascularization without cardiopulmonary bypass (CPB). We describe our experience to demonstrate the feasibility of coronary surgical intervention without CPB in multivessel disease. METHODS: From May 21, 1997, through February 1998, 227 patients underwent revascularization with two or more arterial conduits as the first operation: 122 without CPB (group A) and 105 with CPB (group B). Group A included a greater number of high-risk patients. RESULTS: Mean +/- SD anastomoses per patient were 2.5 +/- 0.6 in group A and 2.8 +/- 0.8 in group B (p = NS). No patient died in group A, whereas 1 patient (0.9%) died in group B. The postoperative complication rate was low in both groups, but intensive care unit and in-hospital stays were shorter in group A than in group B (14.1 +/- 7.1 versus 27.3 +/- 36 hours, p < 0.001, and 4.1 +/- 1.6 versus 5.4 +/- 2.4 days, p < 0.001, respectively [group A versus group B]). Sixty-seven patients in Group A (54.9%) underwent postoperative angiography 33 +/- 35 days after operation. The patency rate was 98.9% (98.2% for the marginal branches). CONCLUSIONS: Arterial revascularization of the coronary arteries without CPB is feasible, with results similar to those obtained with CPB. The two techniques, in our opinion, are complementary, not antagonistic.

Rescue coronary angioplasty: a crotch for limping thrombolysis?

After failed thrombolysis, rescue coronary angioplasty is performed with the aim of restoring complete flow in the infarct-related artery. The clinical benefit of this strategy has been debated in few clinical trials during the early '90s, and high procedure-related risks, low success and early reocclusion rates seemed to outweigh the benefit of mechanical recanalization. The RESCUE trial and, more recently, data from the GUSTO angiographic substudy supported the hypothesis of a better outcome among patients aggressively managed after failed thrombolysis. Noninvasive identification of such patients must be accomplished monitoring electrocardiogram and biochemical markers of myocardial necrosis. Further improvements in the management of candidates to rescue coronary angioplasty can be obtained with a more liberal use of intra-aortic balloon pump among subjects admitted in cardiogenic shock; stents and platelet aggregation inhibitors could reduce early reocclusion, but randomized data are needed to test this hypothesis.

Color duplex scanning for the identification of extracranial atherosclerosis in patients with suspected coronary artery disease.

BACKGROUND: The presence of extracranial artery disease has been used as a predictor of coronary artery disease (CAD). The present study was conducted to test the prevalence of extracranial artery disease among patients with suspected CAD. METHODS: Among candidates for coronary arteriography, 400 consecutive patients (mean age 63 +/- 11 years, 78% males, 22% females) underwent color duplex ultrasound of carotid arteries. RESULTS: Extracranial artery disease was documented in 60 patients (15%), CAD in 309 patients (77%). Patients with extracranial artery disease were significantly older (p < 0.001), smoked a higher amount of pack-years (p < 0.001), showed a higher incidence of diabetes (p < 0.01), hypertension (p < 0.05) and CAD (p < 0.05) when compared to extracranial artery disease-free subjects. Plotting age against extracranial artery disease and CAD distribution, extracranial artery disease occurred later in life than CAD (p < 0.001). The best cut-off point of age for predicting extracranial artery disease was 68 years. Carotid angiography was performed in 114 patients after cardiac catheterization (k = 0.8044 with color duplex scanning). CONCLUSIONS: Extracranial artery disease is frequent among patients undergoing coronary arteriography. Carotid ultrasound screening is useful in older patients.

Percutaneous coronary angioplasty of radial artery conduits.

The higher long-term patency of internal mammary artery grafts has stimulated the search for alternative conduits in order to achieve a complete arterial myocardial revascularization. Percutaneous angioplasty is often the preferred strategy for the treatment of recurrent ischemia in patients who previously underwent bypass surgery, but there is limited experience in the treatment of arterial grafts. We describe two cases of percutaneous treatment of diseased radial artery (RA) grafts. In the first case, two disarticulated stents were deployed through an RA graft: half stent inside the anastomosis to the left anterior descending (LAD) artery, and half stent in the distal LAD artery. Diffuse spasm of the RA graft, resistant to ic nitrates, was successfully reversed after ic calcium antagonists. Absence of restenosis was confirmed two years later. In the second case, after simultaneous catheterization of both the left coronary artery and RA graft, two long stents were implanted in the LAD artery and a final "reversed" kissing-balloon dilation through the stent struts was performed; four months later the patient showed proximal occlusion of the LAD artery and the stenotic RA distal anastomosis was successfully dilated.

Stent implantation versus balloon angioplasty in chronic coronary occlusions: results from the GISSOC trial. Gruppo Italiano di Studio sullo Stent nelle Occlusioni Coronariche.

OBJECTIVES: In this multicenter, randomized trial we evaluated whether stent implantation after successful recanalization of a chronic coronary occlusion reduced the incidence of restenosis. BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) in chronic total occlusions is associated with a higher rate of angiographic restenosis and reocclusion than PTCA in subtotal stenoses. Preliminary reports have suggested a decreased restenosis rate after stent implantation in coronary total occlusions. METHODS: We randomly assigned 110 patients with recanalized total occlusion to Palmaz-Schatz stent implantation, followed by 1 month of anticoagulant therapy versus no other treatment. The primary end point was the minimal lumen diameter (MLD) of the treated segment at follow-up, as determined by quantitative angiography at a core laboratory. RESULTS: Repeat coronary angiography was performed 9 months after the procedure in 88% of patients. The MLD (mean +/- SD) at follow-up was 1.74 +/- 0.88 mm in patients assigned to stent implantation and 0.85 +/- .75 mm in patients assigned to PTCA (p < 0.001). Stent implantation was associated with a lower incidence of restenosis (defined as diameter stenosis > or =50% at follow-up) (32% vs. 68%, p < 0.001) and reocclusion (8% vs. 34%, p = 0.003) than balloon PTCA. Likewise, stent-treated patients had less recurrent ischemia (14% vs. 46%, p = 0.002) and target lesion revascularization (5.3% vs. 22%, p = 0.038), but experienced a longer hospital stay. CONCLUSIONS: Palmaz-Schatz stent implantation after successful balloon PTCA of chronic total occlusions improves the midterm angiographic and clinical outcome and could be the preferred treatment option in selected patients with occluded vessels.

Systematic clinical and angiographic follow-up of patients undergoing minimally invasive coronary artery bypass.

OBJECTIVE: We herein analyze the results of the systematic clinical and angiographic control performed in a series of 77 consecutive patients undergoing minimally invasive coronary artery bypass. METHODS AND RESULTS: From January 1995 to June 1997, 77 patients underwent minimally invasive coronary artery bypass at our institution. There was one inhospital death, one noncardiac late death, and five patients had to be reoperated for graft malfunction. A total of 76 patients underwent postoperative angiographic follow-up. In 66 cases (86.8%) the thoracic artery graft, the target vessel, and the anastomosis were patent and functioning normally. In one case the graft was occluded. In the remaining nine cases the thoracic artery graft was patent but with major anomalies of either the anastomosis, the target vessel, or the course of the thoracic artery. Patients operated using especially designed instruments had angiographic results clearly superior to those of patients operated using conventional instrumentation (perfect patency rate 100% vs 81.8%). At a mean follow-up of 18 months, 98.5% of the surviving patients are asymptomatic with negative myocardial scintigraphy. CONCLUSIONS: The perfect patency rate of minimally invasive revascularization performed without the use of dedicated instruments is unacceptably low. The use of specific devices is likely to result in a substantial improvement in the angiographic results.

An uncommon false aneurysm of the left ventricle.

An 83-year-old woman with previous closed transventricular commissurotomy was admitted for congestive heart failure. Echocardiogram and angiography demonstrated a mitral restenosis and a large-mouthed false aneurysm of the left ventricle.

Integrated approach for revascularization in multivessel coronary artery disease and porcelain aorta.

We report two cases in which combined beating heart revascularization of the left anterior descending artery (LAD) and percutaneous angioplasty of the non-LAD target arteries were adopted after the intraoperative detection of porcelain aorta and impossibility to complete surgical revascularization. This type of strategy preserves the benefits of surgical LAD grafting and complete revascularization and results in a simple and low-risk technical procedure in an otherwise challenging setting.