Intracardiac echocardiography for percutaneous patent foramen ovale and atrial septal defect occlusion.

BACKGROUND: Transesophageal echocardiography (TEE) plays a unique role in transcatheter closure of atrial septal defects (ASD) and patent foramen ovale (PFO). However, problems such as the need for general anesthesia, possible trauma from endotracheal intubation, presence of "blind spots," and occasional inadequate imaging of some cardiac structures have necessitated better imaging techniques. Our study aimed to compare the findings of TEE during the initial diagnostic examination with those from intracardiac echocardiography (ICE) acquired during the interventional procedure. METHODS: A total of 65 patients in whom TEE was used for the diagnosis of ASD or PFO were included. Of these, 40 patients (61.5%) had ASD with significant left to right shunt and 25 (38.5%) patients had PFO associated with transient ischemic attack or stroke. ICE imaging was performed under local anesthesia in all patients to guide interatrial communication closure. RESULTS: ICE provided adequate views of the defects and surrounding structures during the various stages of device deployment. In eight patients (12.3%) an additional anatomical variation was detected. All patients had successful device implantation and were discharged 1 day after the procedure. CONCLUSION: ICE is a safe and high-quality imaging technique for guiding transcatheter ASD and PFO occlusion. Additionally, ICE can both facilitate device implantation and detect cardiac abnormalities that are not identified with TEE during the initial diagnostic investigation.

Coronary artery distensibility in diabetic patients with simultaneous measurements of luminal area and intracoronary pressure: evidence of impaired reactivity to nitroglycerin.

OBJECTIVES: This study investigated whether noninsulin dependent diabetes mellitus (NIDDM) adversely affects the elastic properties of the coronary arteries in patients with coronary artery disease (CAD) and NIDDM. BACKGROUND: Attenuated vascular smooth muscle dilation to exogenous donors of nitric oxide, such as nitroglycerin, has been observed with forearm blood flow studies in patients with NIDDM. METHODS: Twenty patients with CAD and NIDDM (diabetics), and 20 patients with only CAD (nondiabetics) were evaluated. Intracoronary ultrasound (ICUS) imaging with simultaneous intracoronary pressure (P2) recordings were performed at the imaging site with 0.014 in fiber-optic high fidelity pressure monitoring wire. The same wire was used as guide wire for the ICUS catheter. Sites with less than 50% luminal stenosis by ICUS were studied. Recordings were done before and after 300 microg of intracoronary nitroglycerin (IC-NTG). Electrocardiographic tracings recorded simultaneously with ICUS images were used for timing. Systolic and diastolic cross-sectional lumen area (CSLA) and coronary artery distensibility (C-DIST) were measured, C-DIST = [(systolic CSLA-diastolic CSLA)/[(intracoronary pulse pressure) x (diastolic CSLA)]] x 1,000. RESULTS: Diabetics had smaller CSLA (diabetics = 8.6 +/- 0.6 mm2, nondiabetics = 11.5 +/- 0.5 mm2, p < 0.01). Although C-DIST was similar before IC-NTG in the two groups, it became significantly lower in diabetics after IC-NTG (diabetics C-DIST = 3.02 +/- 0.14 mm Hg(-1), nondiabetics C-DIST = 4.21 +/- 0.15 mm Hg(-1), p < 0.01). Degrees of circumference involved, total plaque burden and composition were similar in both groups. CONCLUSIONS: Noninsulin dependent diabetes mellitus reduces C-DIST after IC-NTG administration.

Increased local temperature in human coronary atherosclerotic plaques: an independent predictor of clinical outcome in patients undergoing a percutaneous coronary intervention.

OBJECTIVES: We investigated the midterm clinical significance of human coronary atherosclerotic plaques temperature after a successful percutaneous coronary intervention. BACKGROUND: Previous studies have shown an increased temperature in human atherosclerotic plaques. However, the prognostic significance of atherosclerotic plaque temperature in patients undergoing a successful percutaneous intervention is unknown. METHODS: We prospectively investigated the relation between the temperature difference (deltaT) between the atherosclerotic plaque and the healthy vessel wall and event-free survival among 86 patients undergoing a successful percutaneous intervention. Temperature was measured by a thermography catheter, as previously validated. The study group consisted of patients with effort angina (EA) (34.5%), unstable angina (UA) (34.5%) and acute myocardial infarction (AMI) (30%). RESULTS: The deltaT increased progressively from EA to AMI (0.132 +/- 0.18 degrees C in EA, 0.637 +/- 0.26 degrees C in UA and 0.942 +/- 0.58 degrees C in AMI). The median clinical follow-up period was 17.88 +/- 7.16 months. The deltaT was greater in patients with adverse cardiac events than in patients without events (deltaT: 0.939 +/- 0.49 degrees C vs. 0.428 +/- 0.42 degrees C; p < 0.0001). The deltaT was a strong predictor of adverse cardiac events during the follow-up period (odds ratio 2.14, p = 0.043). The threshold of the deltaT value, above which the risk for an adverse cardiac event was significantly increased, was 0.5 degrees C. The incidence of adverse cardiac events in patients with deltaT > or = 0.5 degrees C was 41%, as compared with 7% in patients with deltaT < 0.5 degrees C (p < 0.001). CONCLUSIONS: Increased local temperature in atherosclerotic plaques is a strong predictor of an unfavorable clinical outcome in patients with coronary artery disease undergoing percutaneous interventions.

Effects of ventricular pacing-induced tachycardia on aortic mechanics in man.

OBJECTIVE: Effects of pacing-induced tachycardia on left ventricular function have been studied extensively. However, little attention has been focused on aortic elastic properties during heart rate increments. The aim was to determine the effects of right ventricular pacing on the aortic elastic properties. METHODS: We studied 14 normal subjects (baseline blood pressure, 129/84 +/- 10/6 mmHg; aortic diameter, 23.5/21.3 +/- 2.4/1.9 mm) at rest, during rapid right ventricular pacing (at five stepwise heart rate increases of 20 bpm every 2 min) and after 5 min recovery. Shifts as well as changes in the slope and the stiffness constant of the pressure diameter (p-d) relation, derived from simultaneous tip-micromanometer aortic pressure recordings and high-fidelity ultrasonic intravascular aortic diameter recordings, were used as indices of aortic stiffness. Wave reflection was also studied. RESULTS: Aortic pulse pressure and strain significantly decreased after pacing-induced tachycardia (p < 0.0001 and < 0.05, respectively). During pacing, the slope of the linear p-d relation as well as the stiffness constant were decreased, followed by increases at recovery (p < 0.0001). The augmentation index and the aortoventricular coupling ratio were significantly decreased (p < 0.0001). CONCLUSIONS: Pacing-induced increases in pulse frequency may result in improved aortic distensibility and aortoventricular coupling.

Valvular heart disease: the influence of changing etiology on nosology.

The many changes in classification of cardiovascular disease during the twentieth century reflect changing etiology of diseases, clinical comprehension and technological advances. In particular, the etiology of valvular heart disease has changed dramatically in the last five decades. The significant reduction of acute rheumatic fever and its sequelae, and the recognition of non-rheumatic causes of valvular disease are responsible for the metamorphosis in the etiology of valvular disorders. Valvular heart disease can be classified as follows: 1) Heritable-congenital causes of valvular heart disease e.g., floppy mitral valve with mitral valve prolapse, bicuspid aortic valve, and the Marfan syndrome; 2) Inflammatory-immunologic causes such as rheumatic fever, acquired immune deficiency syndrome, endocardial proliferative disorders, and antiphospolipid syndrome; 3) Myocardial dysfunction-ischemic cardiomyopathy, dilated or hypertrophic cardiomyopathy-resulting in valvular heart disease; 4) Diseases and disorders of other organs as causes of valvular heart disease, e.g., chronic renal failure and carcinoid heart disease; 5) Valvular heart disease related to aging: calcific aortic stenosis and mitral annular calcification; 6) Valvular disease following interventions such as valvuloplasty, valve reconstructive surgery and valve replacement; and 7) Valvular disease related to drugs and physical agents, such as chronic ergotamine use, radiation therapy and trauma. In clinical practice the most common causes of mitral regurgitation are floppy mitral valve with mitral valve prolapse, ischemic heart disease, dilated cardiomyopathy and mitral annular calcification, while the most common cause of mitral stenosis is rheumatic fever. The most common causes of isolated aortic regurgitation are bicuspid aortic valve and floppy aortic valve, while the most common causes of isolated aortic stenosis are related to the bicuspid aortic valve and the development of calcific senile aortic stenosis. The most common causes of tricuspid regurgitation are dilated cardiomyopathy, ischemic cardiomyopathy, floppy tricuspid valve with tricuspid valve prolapse and infectious endocarditis. Combined mitral and tricuspid regurgitation occur with heritable connective tissue disorders, dilated or ischemic cardiomyopathy, while the most common cause of mitral stenosis plus aortic regurgitation is rheumatic fever. Statistics obtained from cardiac surgery and necropsy may underestimate the true incidence of certain valvular diseases by selection bias. This is particularly so with valvular disease associated with significant ventricular dysfunction, or in the elderly who may not be surgical candidates, or in cases where the valvular disease is not severe enough to require surgical intervention. Recent advances in hemodynamic and imaging technology allow clinicians to define valvular structure and function and to accurately classify valvular heart disease in clinical practice.

Mitral valve prolapse: left ventricular hemodynamics in patients with chest pain, dyspnea or both.

Patients with mitral valve prolapse may present with chest pain and dyspnea. Left ventricular hemodynamics as a cause for these symptoms have not been completely evaluated in these patients. The present study was undertaken to investigate left ventricular hemodynamics in symptomatic patients with mitral valve prolapse. One hundred and three patients with mitral valve prolapse (female 72, male 31, age 56 +/- 11 years) had diagnostic cardiac catheterization for evaluation of chest pain (n = 44), dyspnea (n = 10) and for chest pain plus dyspnea (n = 49). All patients had diagnostic auscultatory findings and angiographic documentation of mitral valve prolapse. Patients with coronary artery disease and mitral regurgitation greater than mild were excluded from the study. Left ventricular end diastolic pressures before (chest pain 9.3 +/- 3.7 mmHg; dyspnea 8.2 +/- 4.2 mmHg; chest pain plus dyspnea 9.3 +/- 4.1 mmHg) and after left ventriculography (chest pain 11.6 +/- 5.5 mmHg; dyspnea 10.2 +/- 2.3 mmHg; chest pain plus dyspnea 11.7 +/- 5.6 mmHg) were normal in the majority of patients and similar in all three groups. Likewise, the left ventricular end diastolic volume index (chest pain 72.0 +/- 16 cm3, dyspnea 69.1 +/- 20 cm3, chest pain plus dyspnea 70.0 +/- 16 cm3) and ejection fraction (chest pain 64.0 +/- 8.4%, dyspnea 64.1 +/- 6.1%, chest pain plus dyspnea 64.3 +/- 6.1%) were normal in the majority of patients and similar in the three groups. Symptomatic patients with mitral valve prolapse without significant mitral regurgitation had normal left ventricular hemodynamics, and their symptoms cannot be explained on the basis of hemodynamic abnormalities alone.

Transluminal extraction catheter atherectomy for the treatment of acute occlusion of an ectatic coronary artery.

Thrombotic occlusion of an ectatic coronary artery may not respond to thrombolytic therapy or balloon angioplasty, since the infarct-related vessel contains a significant amount of thrombus. A patient with acute myocardial infarction of an ectatic right coronary artery that was occluded by a heavy clot burden is described. The patient was treated successfully with transluminal extraction catheter atherectomy and results were confirmed by intravascular ultrasound.

Implantation of stents covered by autologous arterial grafts in human coronary arteries: a new technique.

UNLABELLED: A renewed interest in radial artery conduits for bypass surgery has emerged during the last few years. In order to combine a surgical with a percutaneous technique, stents were covered by radial arterial grafts. The purpose of this study was to evaluate the feasibility of, and the immediate and long-term results after, intracoronary implantation of stents covered by autologous arterial grafts. METHODS: A graft was removed from the radial artery. A conventional stent was then covered by the arterial graft. The autologous arterial graft was stabilized on the stent by sutures. Fifteen covered stents were implanted in 15 patients (56.1 +/- 17.3 years old) in all coronary vessels. RESULTS: The procedure of stent covering was feasible and short in duration. Procedural success was 100% with no in-hospital stent thrombosis, Q-wave myocardial infarction or death. In 14 patients (93.3%), including the patients with clinical restenosis, a repeat angiography was performed (minimum lumen diameter immediately after procedure: 3.01 +/- 0.22 mm, at follow-up: 2.56 +/- 0.90 mm). Target lesion revascularization was required in 2 patients. The event-free survival rate at 2 years was 87%. CONCLUSION: Intracoronary implantation of stents covered by an autologous arterial graft may be performed safely with excellent long-term results. A multicenter study is required to assess the efficacy.

Flavonoids in atherosclerosis: an overview of their mechanisms of action.

Polyphenols are composed of a wide variety of molecules that are classified into several categories, according to their chemical type such as phenolic acids, flavonoids, stilbenes, and lignans. Many studies have proven the beneficial effects of flavonoids in atherosclerosis progression and cardiovascular disease. Dietary flavonoids reduce oxidative stress and exert anti-inflammatory actions. Moreover, flavonoids have the ability to avoid the thrombus formation, improve endothelial function, modify lipid levels and regulate glucose metabolism. In the context of this evidence in this review article we summarize the so far acquired knowledge of the most important mechanisms of action of flavonoids in atherosclerosis progression.

Biomarkers as a guide of medical treatment in cardiovascular diseases.

There is increasing interest in utilizing novel markers of cardiovascular disease risk and consequently, there is a need to assess the value of their use. In this paper, we will review the role of biomarkers in acute coronary syndromes, heart failure and risk stratification for cardiovascular events as guide for treatment scribing. In particular, high sensitivity assays for troponin evaluation detect with greater precision patients with elevated troponin. Therefore, direct and appropriate management is succeeded in these patients with reduction of complications due to earlier treatment, as well. Regarding heart failure, randomized trials that have evaluated biomarker guided treatment approach have not succeeded in establishing specific results for natriuretic peptides (BNP, NT-proBNP) use in terms of therapy guidance. Apart from them, a variety of novel or already used biomarkers, have been tested by small trials for heart failure management, without however, managing to dominate in every day care. Finally, as far as risk stratification for cardiovascular events is concerned, hsCRP has proved to be a strong but doubted biomarker. Therefore, lifestyle and behavioral modification remain the cornerstone of primary prevention.

Coronary artery fistulas in adults: incidence, angiographic characteristics, natural history.

The incidence, angiographic characteristics, and natural history of coronary artery fistulas in patients undergoing diagnostic cardiac catheterization have not been well defined. Of 33,600 patients who had diagnostic cardiac catheterization, 34 (0.1%) had coronary artery fistula. Nineteen fistulas originated from the right, 11 from the left anterior descending, and 4 from the circumflex coronary arteries, respectively. The mean ratio of pulmonary to systemic flow was 1.19 +/- 0.33. Only one patient with coexistent atrial septal defect had a pulmonic to systemic flow ratio > 1.5. Right and left heart pressures, with the exception of three patients in whom left ventricular end-diastolic pressures was > 12 mm Hg, were within normal limits. During a mean follow-up period of 6.3 years (range 2-14 years), there were no complications related to coronary artery fistula. It was concluded that the incidence of coronary artery fistulas detected during diagnostic coronary angiography is very low. Coronary artery fistulas originate predominantly from the right coronary artery and are not associated with hemodynamic abnormalities or other congenital heart diseases. The prognosis of coronary artery fistulas in adults is good.

Aortic stenosis and coronary artery disease caused by alkaptonuria, a rare genetic metabolic syndrome.

Alkaptonuria is a rare metabolic disease in which homogentisic acid deposits occur in various body tissues. We present a case of alkaptonuria which resulted in aortic stenosis and coronary artery disease due to homogentisic acid deposition.

Impaired compensatory coronary artery enlargement in atherosclerosis contributes to the development of coronary artery stenosis in diabetic patients. An in vivo intravascular ultrasound study.

AIMS: Coronary arteries affected by atherosclerosis undergo focal compensatory enlargement, which can be detected by intracoronary ultrasound but not by angiography. Diabetic patients when compared with non-diabetics have a more accelerated progression of coronary artery disease and a more diffuse narrowing of the coronary arteries. Intracoronary ultrasound can clarify if this is due to less compensatory coronary artery enlargement as a response to atherosclerosis. METHODS AND RESULTS: Ten non-diabetic and 15 diabetic patients with coronary artery disease, with angiographically determined one- or two-vessel disease, underwent intracoronary ultrasound examination of the non-stenotic coronary artery. Forty-five sites with luminal stenosis, detected by intracoronary ultrasound, were analysed (15 in non-diabetics, 30 in diabetics). Vessel and lumen area, atherosclerotic plaque area and plaque composition were evaluated. Vessel area was also measured proximal and distal to the healthy segment. In the diabetic patients, there was less vessel area increase from the proximal healthy segment into the atherosclerotic segment than in the non-diabetic patients (99% separate-variance confidence intervals for differences between diabetics' and non-diabetics' means = 0.29 mm2, 2.71 mm2). The proximal plaque free vessel area, the atherosclerotic plaque area and plaque composition were similar between the two groups. CONCLUSION: Diabetics with atherosclerosis have less compensatory coronary artery enlargement than non-diabetics. This may explain the diffuse and accelerated course of coronary artery disease in these patients.

Stent deployment in calcified lesions: can we overcome calcific restraint with high-pressure balloon inflations?

Although significant coronary artery (CA) calcification is believed to affect stent deployment, the exact impact on stent deployment after high-pressure balloon inflations is unknown. Intracoronary intravascular examination (ICUS) was performed in 27 moderate-severe calcified CA lesions before and after stent implantation. In case of unsatisfactory results (in-stent area < 90%, minimal in-stent diameter/maximal in-stent diameter < 0.8), further inflations up to 20 atm guided by ICUS were applied. Initially, stent expansion was adequate in 10 stents (37%) and symmetric in 19 (70%). After inflation at 20 atm, stents with adequate expansion increased to 16 (59%, P = 0.0036), but stents with symmetry decreased to 13 (48%, P = 0.0045). Stent expansion was inversely correlated to the arc of calcium (r = -0.8, P < 0.0001). There were five patients with clinical restenosis at 6 months (18%). Increases in stent lumen area with high-pressure balloon inflations in moderate-severe calcified CA lesions are at the expense of symmetry. This may affect clinical restenosis.

Thermography of human arterial system by means of new thermography catheters.

In this case report, we present the first clinical application of three thermography catheters for temperature measurements in the coronary arteries, the aorta, and the femoral arteries. The entire procedure was performed successfully without complications. Larger clinical studies are required in order to examine the feasibility for the application of the aortic and the peripheral artery thermography catheters and the clinical significance of temperature measurements in these arteries. Cathet Cardiovasc Intervent 2001;54:51-58.

Autologous vein graft-coated stents for the treatment of thrombus-containing coronary artery lesions.

Recent studies have shown that stents may have a potential role in the treatment of thrombus-containing lesions. We report on the application of an autologous vein graft-coated stent (AVGCS) as the primary therapeutic modality for acute myocardial infarction in 10 patients. AVGCS delivery and deployment were successful and uneventful. Mean minimal lumen diameter and TIMI trial flow grade increased significantly (from 0.04 +/- 0.09 mm pre-AVGCS to 3.02 +/- 0.32 mm post-AVGCS, and from 10 patients with flow grade 0-1 pre-AVGCS to 10 patients with flow grade 3 post-AVGCS, respectively). Ten-day angiogram revealed maintenance of the immediate results. Nine patients had a negative exercise stress test 2 mo post-AVGCS, and at a mean follow-up of 30 +/- 7 weeks, all 9 were symptom-free. One patient, 3 wk after implantation and while being hospitalized for hypovolemic shock, developed recurrent infarction. These favorable preliminary outcomes suggest that AVGCS may play a useful role in the treatment of thrombus-containing lesions.

Autologous vein graft-coated stent for treatment of coronary artery disease.

Acute or subacute thrombosis and late restenosis remain the main limitations of permanent stenting. In an effort to address these limitations, an autologous vein graft-coated stent (AVGCS) was developed at our institution. This stent consists of a conventional stent (Palmaz or Palmaz-Schatz, Johnson and Johnson), which is covered by an autologous vein graft. After successful experimental implantation, we report here the immediate results of the percutaneous implantation of AVGCS in 7 patients with coronary artery disease (6 de novo lesions and 1 bailout case). The results of this preliminary study indicate that the preparation of the AVGCS is easy and feasible. The implantation of the AVGCS was uncomplicated, and the immediate angiographic results were excellent. This new type of coated stent may be useful in addressing current limitations of balloon angioplasty.

Left atrial volumes and function in orthotopic cardiac transplantation.

Early ventricular filling and therefore passive left atrial emptying may be impaired in patients with cardiac transplantation. As a result, left atrial function may be an important factor in maintaining stroke volume in recipients of orthotopic cardiac transplants. Left atrial volumes maximal (mitral valve opening), minimal (mitral valve closure), and onset of atrial systole (P wave on electrocardiogram) were determined by echocardiography using the biplane area-length method in 12 patients after cardiac transplantation and 12 control subjects. Maximal and minimal left atrial volumes and left atrial volumes at onset of atrial systole were larger in patients who had cardiac transplantation than in control subjects (89.8 vs 41.8 cm3, 48 vs 15.2 cm3, and 70.4 vs 27.0 cm3, respectively; p < 0.01). In patients undergoing cardiac transplantation, good correlations were found between left atrial maximal volume and left ventricular mass (r = 0.56) and between left atrial maximal volume and mean pulmonary capillary wedge pressure (r = 0.81). Left atrial passive emptying volume (maximal minus volume at P wave), was not statistically different between the two groups (19.3 in patients receiving transplants vs 14.7 cm3 in control subjects), but left atrial stroke volume (beginning atrial systole to minimal) was larger in patients receiving transplants than in control subjects (22.4 vs 11.8 cm3, respectively; p < 0.001). Thus left atrial contraction contributed 42% to the left ventricular stroke volume in patients who had cardiac transplantation but only 17% in control subjects (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Stents covered by autologous venous grafts: feasibility and immediate and long-term results.

BACKGROUND: Previous experimental studies with a new covered stent, the autologous venous graft-covered stent (AVGCS), have shown favorable results. The aim of this study was to evaluate the feasibility and safety of this new technique in human coronary arteries and to compare the long-term outcome with uncovered stents. METHODS AND RESULTS: A venous graft was removed from an upper limb. A conventional stent then was covered by the venous graft. Fifty-eight AVGCS were implanted in 56 patients, including 16 patients with acute coronary syndromes (ACS). Additionally, in 114 patients, 138 uncovered stents were implanted, serving as a control group, including 38 patients with ACS. The procedure was successful in all patients. Stent thrombosis was observed in 3 patients in the control group and in 1 patient with an AVGCS. There was a trend for the minimal luminal diameter to be greater in the AVGCS group at follow-up (P =.07), and statistical significance was observed in patients with ACS (P <.01). The target vessel revascularization and the restenosis rates were similar between the 2 groups. In patients with ACS, the restenosis rate was less (P <.04) and there was a trend for target vessel revascularization to be less in covered stents (P =.09). The event-free survival rate at 4 years was 85% in the AVGCS group versus 81% in the control group (P = not significant); in ACS it was 94% versus 78%, respectively (P = not significant). Stents covered by thicker venous grafts were associated with improved clinical outcome. CONCLUSIONS: Stents covered by autologous venous grafts may be safely prepared without complications. This technique may prove to be a useful means, especially in patients with ACS.