Tracking coronary calcification by using dual-section spiral CT: a 3-year follow-up

PURPOSE

To investigate the accuracy of dual-section spiral computed tomography (CT) in tracking the progression of coronary calcification, as measured during a 3-year follow-up.

MATERIALS AND METHODS

Two hundred forty-six patients with hypertension (mean age, 66 years +/- 6 [SD]) were preselected in accordance with the International Nifedipine Study Intervention as a Goal for Hypertension Therapy protocol. Subjects had no clinical coronary arterial disease prior to the study and no cardiovascular events during follow-up. All participants underwent baseline CT (3.2-mm section thickness; reconstruction increment, 1.5 mm) and follow-up CT after 3 years. Calcification progression was defined as any increase in total calcification score (TCS) and analyzed in accordance with five baseline TCS categories: 1-9, 10-35, 36-100, 101-250, and greater than 250.

RESULTS

At baseline CT, 152 patients had a TCS greater than 0, and 106 (70%) showed progression after 3 years, while 94 had a baseline TCS of 0; of these, 26 (28%) showed progression (P: <.01 between groups). The mean TCS was significantly higher in each baseline TCS category after 3 years. The percentage increase was negatively correlated with baseline TCS (P: <.01) and ranged from 466% in the lowest category to 38% in the highest.

CONCLUSION

Dual-section spiral CT depicts significant change in TCS over time and is useful in tracking calcified coronary atherosclerosis.

Gender paradox in cardiac calcium deposits in middle-aged and elderly patients: mitral annular and coronary calcifications interrelationship

OBJECTIVES

mitral annular calcification (MAC) occurs mainly in middle-aged and elderly patients and can lead to serious clinical consequences. Male predominance in the prevalence of coronary disease is well-established. Paradoxically, the prevalence of MAC, which is theoretically based on the same etiological mechanisms as coronary atherosclerosis, seems to be predominant in postmenopausal women. The goal of this work was to investigate gender influences on interrelationship between MAC and coronary calcifications (CC) in the same population of middle-aged and elderly patients with increased cardiovascular risk.

METHODS

the study comprised 522 patients (284 men and 238 postmenopausal women, aged 52-80 years, mean 65+/-6), who were recruited to the International Nifedipine GITS Study of Intervention as a Goal in Hypertension Treatment (INSIGHT) study in our region. They underwent both fast spiral computed tomography of the heart and echo-Doppler. MAC was defined as advanced when its thickness was > or =5mm; otherwise it was defined as trivial.

RESULTS

there were 37 (16%) women and 25 (9%) men with advanced MAC (AMAC), 97 (41%) women and 118 (42%) men with trivial MAC and 104 (44%) women and 141 (50%) men without MAC. The prevalence of any type of CC was significantly higher among men (P=0. 001). In sharp contrast to the distinct male predominance in coronary disease, AMAC was more prevalent among women. In patients without CC prevalence was 9 and 4%, increasing to 16 and 8% in those with nonsevere CC and to 38 and 14% in patients with severe CC, respectively (P=0.001). Multivariate analysis showed that AMAC can predict the presence of severe CC in women and men, with OR of 4.1 and 2.6 (CI 1.2-14.8 and 1.0-10.6) and coronary disease with OR of 2. 5 and 2.5 (CI 0.6-10.6 and 1.0-6.4), respectively.

CONCLUSIONS

AMAC signifies a high probability of coronary atherosclerosis in patients of both genders. The inverted gender predominance in the prevalence of annular calcification and CC could be explained by additional etiological (likely osteoporotic) mechanisms of MAC development among postmenopausal women.

Attenuated responses of Doppler-derived hemodynamic parameters during supine bicycle exercise in heart transplant recipients

The aim of this study was to characterize Doppler-derived hemodynamic parameters in heart transplant recipients at rest and during symptom-limited supine bicycle exercise. Eighteen sedentary patients aged 54.0 +/- 2 years, 1.6 +/- 1.0 years following cardiac transplantation, and 18 sedentary healthy volunteers aged 51.8 +/- 4 years were investigated. Basic hemodynamic parameters and Doppler-derived parameters were recorded at rest and at peak dynamic exercise. Resting heart rate, blood pressure and rate-pressure product were higher in the transplanted patients (p < 0.001). However, in comparison with the resting state, the increase in these parameters at exercise was lower in heart transplant recipients. In the healthy, dynamic exercise induced an increase in peak flow velocity, mean acceleration, flow velocity integral, stroke volume, cardiac output and cardiac index (p < 0.001 for all) while systemic vascular resistance, ejection time and acceleration time decreased (p < 0.001 for all). The following parameters increased in the transplanted patients at dynamic exercise: peak flow velocity, cardiac output and cardiac index (p < 0.001), mean acceleration (p < 0.01) and flow velocity integral (p < 0.05). Ejection time decreased (p < 0.05) and acceleration time and systemic vascular resistance remained unchanged. In conclusion, at rest peak flow velocity, mean acceleration, flow velocity integral and stroke volume are lower in the transplanted than in the healthy controls, while cardiac output, cardiac index and systemic vascular resistance are equal. Our study demonstrates attenuated responses of basic hemodynamic parameters and Doppler-derived cardiovascular indices at symptom-limited supine bicycle exercise in heart transplant recipients compared to healthy volunteers.

Intermediate but not low doses of aspirin can suppress angiotensin-converting enzyme inhibitor-induced cough

This self-matched control study aimed to compare the efficiency of two different regimens of active treatment: aspirin in low (100 mg daily) versus intermediate (500 mg daily) doses in abolishing angiotensin-converting enzyme inhibitor (ACEI)-induced cough. A dry bothersome cough is the most common adverse class effect of all angiotensin-converting enzyme inhibitors. Prostaglandins (PG) have been pinpointed as playing a leading role in the genesis of ACEI-associated cough. The role of different doses of the most commonly used PG inhibitor-aspirin-in ACEI cough modification was not yet elucidated. Of 350 consecutive ACEI-treated patients, we identified 34 (9.7%) nonsmoking ACEI-related coughers. Patients with lung disease, nonsteroidal anti-inflammatory drug (NSAID) treatment, and those who did not agree to participate in the study were excluded. In the remaining 14 ACEI coughers (eight men, six women; mean age, 63 +/- 11 years), the treatment was discontinued; the dry cough completely disappeared, but returned in all patients within 1 week after ACEI reintroduction. At the end of the rechallenge period, patients started a low dose of aspirin for 1 week, switching thereafter to the intermediate dose of aspirin for an additional week. On each visit the cough severity (CS, 0-4) and frequency (CF, 0-10) scores were registered. Low doses of aspirin were ineffective in suppressing ACEI-induced cough, whereas intermediate doses completely abolished cough in five patients and reduced coughing in all but one patient; CS and CF decreased, respectively, from 2.5 +/- 1.0 to 0.9 +/- 1.1, P < .002 and from 6.6 +/- 2.4 to 2.4 +/- 1.1, P < .0002. Overall, intermediate doses of aspirin beneficially modified cough scores in 13 (93%) patients, enabling nine (64%) to continue ACEI treatment. Aspirin did not influence blood pressure control either in hypertensives or in postinfarction patients. We conclude that intermediate but not low doses of aspirin probably can suppress ACEI-induced cough. These findings propose a new alternative therapeutic approach for patients with ACEI-related cough, especially those in whom ACEI treatment seems to be essential.

Advanced mitral annular calcification is associated with severe coronary calcification on fast dual spiral computed tomography

RATIONALE AND OBJECTIVES

Mitral annular calcification (MAC) may be a form of atherosclerosis and can lead to serious clinical consequences. The possible linkage between the presence and extent of MAC and coronary calcium score on CT is unknown. The goal of the present study was to investigate whether an association between MAC and coronary calcification (CC) exists in hypertensive patients with increased cardiovascular risk.

METHODS

Five hundred twenty-two patients (284 men and 238 women, age range 52-80 years, mean 65+/-6 years), who were recruited to the INSIGHT study in the authors' region, underwent fast spiral CT of the heart as well as an echo Doppler examination. MAC was defined as advanced when the thickness of the calcium deposit was 5 mm or more; it was defined as trivial otherwise.

RESULTS

The advanced MAC group comprised 62 patients, the trivial MAC group 215 patients, and the control group (without MAC) 245 patients. The prevalence of nonsevere CC was similar among the study groups, whereas the prevalence of severe CC (total calcium score >300) and the prevalence of proven coronary artery disease were associated with the presence and extent of MAC: respectively, 12% and 15% in control patients, 18% and 20% in patients with trivial MAC, and 29% and 29% in patients with advanced MAC. Multivariate analysis identified advanced MAC as an independent variable associated with severe CC and proved coronary artery disease.

CONCLUSIONS

The results of this study demonstrated an association of advanced MAC and severe CC on spiral CT and proved coronary artery disease on the clinical level. Thus, advanced but not trivial MAC makes the noninvasive diagnosis of coronary atherosclerosis more likely and presumably could be considered as a new indication for further coronary evaluation in high-risk patients.

Spiral computerized tomography (dual helical mode) as a detector of aortic atheromas in patients with stroke and systemic emboli: additional benefit of the contrast-enhanced technique

BACKGROUND

Protruding aortic atheromas are a potential source of stroke and systemic emboli. The single modality currently available for their detection has been transesophageal echocardiography. However, TEE does not allow full visualization of the upper part of the ascending aorta and proximal aortic arch.

OBJECTIVES

To investigate whether double helical computerized tomography--both with and without contrast injection--may represent a useful technique for noninvasive detection of PAA in stroke patients.

METHODS

Forty consecutive patients > or = 50 years of age who sustained a recent ischemic stroke and/or systemic emboli (within 15 days after the onset of the event) were enrolled in the study and underwent TEE and DHCT without contrast injection using thin slice acquisition (3.2 mm thickness and 1.5 mm reconstruction increment). In addition, the last eight consecutive patients, after obtaining an unenhanced scan, underwent a contrast-enhanced DHCT following peripheral intravenous injection of a small amount of contrast material (15 ml of diatrizoate).

RESULTS

PAAs were demonstrated by TEE in 18 patients (45%); in 16 of them (89%) the atheromas were recognized by DHCT. Of the 22 patients without PAA on TEE, DHCT confirmed their absence in 18 (82%). DHCT yielded a sensitivity of 89%, a specificity of 82%, and an overall accuracy of 85%. The total number of protruding plaques detected by TEE was 43, of which 41 (95%) were correctly identified by DHCT. The mean thickness of the plaques was 5.6 +/- 2.4 mm on TEE, and 5.4 +/- 2.3 on DHCT (P = NS), with a good correlation between the modalities (r = 0.84). Contrast-enhanced DHCT scans demonstrated absolute equivalence to TEE in aortic areas defined as "clearly visualized by TEE." DHCT detected PAA between the distal ascending aorta and the proximal arch in seven patients; these atheromas were not included in the comparative analysis. In these "occult" areas, DHCT may be superior to TEE.

CONCLUSIONS

DHCT without contrast injection using thin slice acquisition may become a useful modality for rapid noninvasive detection of PAA. Contrast-enhanced DHCT scans significantly improve imaging quality and may be superior to TEE in the upper ascending aorta and the proximal arch (areas not well visualized by TEE).

The acute effects of sublingual estradiol on left ventricular diastolic function in normotensive and hypertensive postmenopausal women

AIM

limited information is available on estrogen influences on diastole. We aimed to investigate the acute effects of a single dose of sublingual 17beta-estradiol on left ventricular diastolic function in postmenopausal women.

METHODS

the study included 28 women aged 55.6 +/- 6 (15 normotensive and 13 hypertensive), who underwent Doppler echocardiography and estradiol plasma levels determination before and 60 min after sublingual administration of 4 mg of 17beta-estradiol.

RESULTS

there were no modifications in heart rate. Both systolic and diastolic blood pressure dropped significantly in the hypertensives and remained unchanged in normotensives. Estradiol levels were 1790 +/- 869 pg/ml in the normotensives and 2664 +/- 1490 in the hypertensives (P < 0.05). Peak early velocity, in the population as a whole, increased from 84 +/- 18 to 91 +/- 18 cm/s and the early-to-atrial velocity ratio from 1.1 +/- 0.4 to 1.4 +/- 0.6 (P < 0.0001 for both). Both acceleration and deceleration rates increased significantly (P < 0.0001). These changes were shared by all the patients. In addition, the hypertensive patients, who presented a baseline pattern characterized mainly by a grossly increased peak atrial velocity with reduction in the early-to-atrial velocity ratio, demonstrated a decrease in peak atrial velocity from 92 +/- 12 to 78 +/- 10 cm/s (P < 0.0001), associated with significant reductions in deceleration time (P < 0.0001) and pressure half time (P < 0.005). Therefore, the typical picture of impaired ventricular relaxation was favorably changed after estradiol administration.

CONCLUSIONS

the sublingual administration of estradiol induces acute modifications in left ventricular diastolic function in postmenopausal women, with improvement in the age-related left ventricular relaxation pattern, and that these beneficial changes are more pronounced in hypertensive that in normotensive women.

Antihyperglycemic treatment in diabetics with coronary disease: increased metformin-associated mortality over a 5-year follow-up

Mortality rates are considerably higher in chronic ischemic heart disease (IHD) patients with non-insulin-dependent diabetes mellitus (NIDDM) than in those who are nondiabetics. The relationship between different types of antihyperglycemic pharmacological therapy and mortality rate in this NIDDM population is uncertain. We aimed to examine the survival in NIDDM patients with IHD using various types of oral antidiabetic treatments over a 5-year follow-up period. The study sample comprised 11,440 patients with a previous myocardial infarction and/or stable anginal syndrome, aged 45-74 years, who were screened, but not included in the Bezafibrate Infarction Prevention study. Among them, 9,045 were nondiabetics and 2,395 diabetics. The diabetic patients were divided into four groups on the basis of their therapeutic regimen at screening: diet alone (n = 990), sulfonylureas (n = 1,041), metformin (n = 78) and a combination of a sulfonylurea and metformin (n = 266). All NIDDM groups were similar with regard to age, gender, hypertension, smoking, heart failure, angina and prior myocardial infarction. Crude mortality rate was lower in the nondiabetic group (11.21 vs. 21.8%; p < 0.001). In the diabetic group, mortality was 18.5% for patients on diet alone, 22.5% for those on sulfonylureas, 25.6% for patients on metformin, and 31.6% for the combined sulfonylurea/metformin group (p < 0.01). When analyzing age-adjusted mortality rate and actuarial survival curves, the lowest mortality was found in patients on diet alone and the highest in patients on metformin (alone or in combination with sulfonylureas). After adjustment for variables connected with long-term prognosis, the use of metformin was associated with increased relative risk (RR) for all-cause mortality of 1.42 (95% CI 1.10-1.85), whereas the use of sulfonylureas alone was not [RR 1.11 (95% CI 0.90-1.36)]. NIDDM patients with IHD using metformin, alone or in combination with sulfonylureas, exhibited a significantly increased mortality. Until the results of problem-oriented prospective studies on oral control of NIDDM will be available, alternative therapeutic approaches should be investigated in these patients.

Effectiveness of nifedipine GITS in combination with atenolol in chronic stable angina

Nifedipine gastrointestinal therapeutic system (GITS) is a once-daily formulation of nifedipine that provides stable plasma concentrations over the entire 24 h dosing interval. Two-hundred and one patients with Canadian Cardiovascular Society class II to III angina who were on 50 mg of atenolol yet still experiencing angina symptoms were randomized to receive either placebo or nifedipine GITS 30, 60 or 90 mg/day. After four weeks of treatment, the changes in time from baseline to onset of 1 mm ST segment depression in the 183 eligible patients were 26.7+/-10.2 s, 40.9+/-11.3 s, 63.2+/-12.9 s and 70.3+/-12.6 for the placebo, and 30, 60 and 90 mg/day groups, respectively. These differences were significant (P<0.05) for the 60 and 90 mg/day groups compared with placebo and for the 60 mg/day group compared with the 30 mg/day group. The times to onset of pain and termination of exercise showed similar prolongation but did not achieve statistical significance. During the one-year open label phase of the study, patients exhibited statistically significant improvements in the time to onset of ST segment depression, time to anginal pain and time to termination of exercise at a mean dose of 52.3 mg/day of nifedipine GITS. Adverse events were primarily vasodilatory in nature. This study supports the use of nifedipine GITS in patients with chronic stable angina inadequately controlled on beta-blocker alone.

Lack of effects of transdermal estradiol on diastolic function: a randomized placebo-controlled double-blind short-term trial

OBJECTIVE

Limited information is available on the effects of transdermal estradiol on diastole. The present study was a randomized double-blind placebo-controlled trial designed to investigate the short-term effects of transdermal estradiol on left ventricular diastolic function in postmenopausal women.

METHODS

The study included 45 women aged 50.8 +/- 3.6 years (25 randomized to the study group and 20 to placebo), who underwent Doppler echocardiography and determination of the plasma estradiol level after 4 and 8 weeks of transdermal estradiol administration in a dose of 50 micrograms per 24 h.

RESULTS

There were no modifications in heart rate. Systolic blood pressure dropped in the study patients after 8 weeks (p < 0.03); diastolic blood pressure remained unchanged. Estradiol levels were 67 +/- 36 pg/ml at 4 weeks and 70 +/- 49 pg/ml at 8 weeks in the study group. Basal values of peak early and peak atrial velocities, acceleration time and rate, deceleration time and rate, early/atrial velocity ratio and pressure half-time were not significantly different between the estradiol and placebo groups. Doppler values remained unchanged after both 4 and 8 weeks in women receiving estradiol. Women with relatively high serum 17 beta-estradiol levels (> 100 pg/ml) at 4 or 8 weeks of treatment did not present more pronounced changes in the Doppler-derived parameters compared with patients with low hormone levels.

CONCLUSION

The results showed a lack of short-term effects of transdermal estradiol on left ventricular diastolic function in postmenopausal women, irrespective of serum estradiol levels.

Prevalence and prognostic significance of unrecognized systemic hypertension in patients with diabetes mellitus and healed myocardial infarction and/or stable angina pectoris

Few data are available regarding the prevalence and prognostic significance of the triple coexistence of undiagnosed systemic hypertension, diabetes mellitus, and coronary heart disease. This study aimed to evaluate the prevalence and prognostic significance of unrecognized hypertension in cardiac diabetic patients previously defined as "normotensives" over a 5-year follow-up period. The study sample comprised 11,515 patients aged 45 to 74 years with a previous myocardial infarction and/or anginal syndrome who were screened but not included in the Bezafibrate Infarction Prevention study. Among them, 9,033 were nondiabetics and 2,482, diabetics. The diabetics were divided into 3 groups: (1) 1,272 normotensives, (2) 152 patients without history of hypertension but with elevated blood pressure ("unrecognized hypertensives"), and (3) 1,058 hypertensives with established diagnosis. The prevalence of both diagnosed and unrecognized hypertension in diabetics pooled together increased from 49% to 69% when World Health Organization and new Joint National Committee-VI criteria were compared. Crude all-cause mortality was lower in nondiabetics than in diabetics (11.2% vs 22.0%; p <0.001). Among diabetics the lowest all-cause mortality was documented for normotensives (19.3%), whereas the highest mortality was observed in unrecognized hypertensives (26.3%, p = 0.003). Both unrecognized and established hypertensives demonstrated a significant stroke-related mortality excess: about four- and threefold increases in cerebrovascular accident-related death, respectively, were observed (p = 0.002). On multivariate analysis, both unrecognized and diagnosed hypertension were consistent predictors of increased all-cause mortality, with a hazard ratio of 1.28 (95% confidence interval 0.90 to 1.82) and 1.24 (95% confidence interval 1.03 to 1.49), respectively. Our findings demonstrate widespread undiagnosed hypertension in diabetic coronary patients; their 5-year mortality was significantly increased compared with normotensives, and tended to be even higher than in diabetics previously identified as hypertensives.

Double-helical CT as a new tool for tracking of allograft atherosclerosis in heart transplant recipients

RATIONALE AND OBJECTIVES

Tracking the progression of allograft atherosclerosis in heart transplant recipients is currently accomplished using invasive techniques. If its monitoring feasibility is demonstrated, spiral CT could be a non-invasive alternative for this objective.

METHODS

Twenty-four consecutive heart transplant patients (21 men, 3 women, mean age 55 +/- 11 years) were scanned using double-helical CT. The first scan was performed 1.9 +/- 1.3 years after transplantation. After 2 years of follow-up, 4 patients died and the remaining 20 underwent a second scan. All scans were performed according to a previously reported double-helical CT protocol.

RESULTS

The incidence of coronary calcification at the first scan was 4.2% (1/24); it increased to 40% (8/20) at the second scan (P < 0.001). Spiral CT identified new but very mild calcific deposits in seven patients with a mean total calcium score of 6.7 +/- 4.0.

CONCLUSIONS

Double-helical CT is a viable tool to diagnose and track newly developed allograft atherosclerosis.

Hypertension in diet versus pharmacologically treated diabetics: mortality over a 5-year follow-up

The natural history of non-insulin-dependent diabetes mellitus (NIDDM) differs markedly between patients with diet treated and pharmacologically treated disease. However, the interrelationship between hypertension and these common diabetes types has not been specifically addressed in previous studies. This study was designed to evaluate the prognostic significance and prevalence of hypertension in coronary patients with diet versus pharmacologically treated NIDDM over a 5-year follow-up period. The study sample comprised 11 515 patients aged 45 to 74 years with a previous myocardial infarction and/or anginal syndrome who had been screened but were not included in the Bezafibrate Infarction Prevention study. Among them, 9033 were nondiabetics and 2482, diabetics (987 diet treated and 1495 pharmacologically treated). The prevalence of hypertension among nondiabetics, diet-treated diabetics, and pharmacologically treated diabetics was 31%, 42%, and 43%, respectively. Crude all-cause mortality (CM) was lower in the nondiabetic patients (11.2% versus 22.0%; P<0.001). Among diabetics, 548 patients died: 81 diet treated normotensives (CM 14%); 100 diet-treated hypertensives (CM 24.4%); 205 pharmacologically treated normotensives (CM 24.2%); and 162 pharmacologically treated hypertensive patients (CM 25.0%). Age-adjusted mortality was lowest for the normotensive patients in the diet-treated group and highest for the hypertensive pharmacologically treated patients. Multivariate analysis shows that hypertension is a strong and independent predictor of increased CM in diet-treated but not in pharmacologically treated NIDDM: hazard ratio (HR) was 1.68 (95% confidence interval [CI] 1.24 to 2.29) for the diet-treated versus 1. 01 (95% CI 0.82 to 1.26) for the pharmacologically treated diabetics. The contribution of hypertension to stroke mortality was substantial for both diet treated and pharmacologically treated NIDDM: hazard ratios were 3.17 (95% CI 1.12 to 8.98) and 2.21 (95% CI 0.72 to 6.77), respectively. The increased risk of mortality associated with hypertension in relatively mild diet-treated NIDDM strongly supports the clinical benefit of early blood pressure control among diabetic patients with ischemic heart disease.

The nitric oxide pathway: is L-arginine a gate to the new millennium medicine? A meta-analysis of L-arginine effects

BACKGROUND

During the past ten years, there has been a growing interest in L-arginine (LA), a semi-essential amino acid, which has recently been shown as a physiological precursor of nitric oxide (NO).

AIM

The aim of this study is to determine the current role of LA in both cardiovascular and general medicine.

METHODS

We performed MEDLINE searches covering a period of 33.5 years (January 1966 to July 1999) for "L-arginine" (unlimited search). Since we focused on the potential importance of LA for clinical medicine, we added the term "disease" to limit the search (limited search).

RESULTS

During the period of interest 25883 articles devoted to the issue were found on unlimited search, whereas only 1656 on the limited one (mean annual rate 772 and 49 articles per year, respectively). Drastic elevation in annual rate both for unlimited and limited searches were found during the last 5 years - 2055 and 194 articles per year, respectively. The effects of LA dietary supplementation at relatively high doses have been studied extensively in several populations. LA exerts favorable effects in the prevention and treatment of cardiovascular disorders associated with endothelial dysfunction, atherogenesis and thrombosis. On the basis of the data from experimental and clinical studies, the long term oral LA supplementation has proven to be useful in avoiding endothelial damage and restoring injured endothelial function in patients with cardiovascular risk factors (hypercholesterolemia, smoking, diabetes, advanced age) or with several chronic cardiovascular disorders, such as coronary disease, peripheral and cerebral vascular disease, mild and moderate heart failure. Intravenous LA administration is likely to represent a potentially novel therapeutic strategy in hospitalized patients with critical limb ischemia, during angioplasty, coronary bypass grafting and cardiac transplantation. In addition, LA led to an improvement in interstitial cystitis symptoms, male reproductive activity, recovery from trauma and prognosis of chemotherapy in breast cancer.

CONCLUSION

Our data clearly demonstrate a significant growth of interest in LA in clinical medicine. Arginine is gaining a prominent position as a part of the therapeutic arsenal in the management of LA-NO pathway-related disorders.

L-Arginine: rediscovery in progress

Since the recognition that L-arginine (LA) is the natural metabolic donor of nitric oxide, this amino acid has reached the medical spotlight. LA exerts favorable effects in the prevention and treatment of endothelial damage and the restoration of endothelial function in patients with cardiovascular risk factors (hypercholesterolemia, smoking, hypertension, diabetes and advanced age) or with several chronic cardiovascular disorders (coronary, peripheral and cerebral vascular disease, and mild-to-moderate heart failure). LA administration is likely to represent a potentially novel therapeutic strategy during angioplasty, coronary bypass grafting and cardiac transplantation. More conclusive research findings for the rediscovered role of this well-known substance merit close attention.

The effects of sublingual estradiol on left ventricular function at rest and exercise in postmenopausal women: an echocardiographic assessment

OBJECTIVE

To evaluate the acute hemodynamic effects of 4 mg estradiol given sublingually.

DESIGN

Rest and exercise echocardiographies were performed prior to estradiol administration. Then, another set of tests was done post-dose: rest examination at 1 h post-dose, isometric exercise at 65 min post-dose, and dynamic exercise at 100 min post-dose.

RESULTS

The administration of 4 mg sublingual estradiol to 24 postmenopausal women (aged 48-58 years) was followed 60 min post-dose by a surge in mean estradiol serum levels (1759 +/- 704 pg/ml). At rest a slight drop in systolic and diastolic blood pressure was measured after estrogen ingestion: 132 +/- 24 mm Hg versus 127 +/- 21 mm Hg, p < 0.05; 83 +/- 11 mm Hg versus 78 +/- 10 mm Hg, p < 0.02. There were no changes in resting heart rate, double product, or vascular resistance. The left heart cavities became smaller: the left atrium diameter decreased from 33.7 +/- 4 mm to 32.3 +/- 4 mm, p < 0.01; the end-systolic diameter decreased from 24.9 +/- 3 mm to 23.6 +/- 4 mm, p < 0.01; the end-diastolic diameter decreased from 44.5 +/- 4 mm to 42.7 +/- 4 mm, p < 0.01. The peak aortic blood flow velocity fell from 120 +/- 19 cm/s to 116 +/- 22 cm/s (p < 0.05), and the flow velocity integral fell from 26.3 +/- 4 cm to 24.9 +/- 5 cm (p < 0.01); the cardiac output underwent a small change, with borderline significance: 7 +/- 2 L/min versus 6.7 +/- 2 L/min, p = 0.06. Only minor changes in the hemodynamic and echocardiographic parameters were recorded after estrogen for both isometric and dynamic exercises. Analyses were also made for two subgroups: 13 normotensive women were compared with 11 hypertensive women. The post-estrogen decreases in resting blood pressure and in peak blood velocity were observed only in the hypertensive subjects, whereas the changes in heart dimensions and in flow velocity integral were the same in both subgroups.

CONCLUSIONS

Sublingual estradiol was associated with acute hemodynamic alterations mainly at rest but also after exercise.

Dual-helical CT for detecting aortic atheromas as a source of stroke: comparison with transesophageal echocardiography

PURPOSE

To investigate whether unenhanced dual-helical computed tomography (CT) is useful in the rapid, noninvasive detection of protruding aortic atheromas.

MATERIALS AND METHODS

Thirty-two consecutive patients at least 50 years of age who had recent ischemic stroke, systemic emboli, or both, underwent transesophageal echocardiography (TEE) and unenhanced dual-helical CT with thin sections (section thickness, 3.2 mm; reconstruction increment, 1.5 mm).

RESULTS

TEE demonstrated protruding aortic atheromas 15 patients (47%); dual-helical CT depicted protruding aortic atheromas in 13 of those 15 patients (87%). Of the 17 patients without a protruding aortic atheroma at TEE, dual-helical CT helped confirm the absence in 14 (82%). Dual-helical CT yielded a sensitivity of 87%, a specificity of 82%, and an overall accuracy of 84%. Thirty-six protruding plaques were detected with TEE, of which 34 (94%) were correctly identified with dual-helical CT. Of those 34 plaques, 27 (79%) contained variable amounts of calcium and seven (21%) showed hypoattenuation suggestive of soft plaques and thrombi. In six patients, dual-helical CT depicted a protruding aortic atheroma between the distal ascending aorta and the proximal arch; these plaques were not included in the comparative statistics and were analyzed separately.

CONCLUSION

Unenhanced dual-helical CT with thin sections appears to be useful for the rapid, noninvasive detection of a protruding aortic atheroma, especially in areas not clearly visualized with TEE.

Disrupted mobile aortic plaques are a major risk factor for systemic embolism in the elderly

Protruding aortic plaques--especially those with mobile properties--on transesophageal echocardiography (TEE) are a potential source of stroke and systemic embolism in the elderly. Whether the various morphologies of atheromas with mobile components represent potential differences in the risk for embolic events has not been thoroughly elucidated. The goal of the present study was to determine the association between embolic events and the various types of mobile lesions in the thoracic aorta. Our population consisted of 569 consecutive patients (age 18-83 years) referred for TEE over 27 months; 108 (19%) of them were referred to evaluate recent embolism (cerebral in 97 and peripheral or both in 11; group I) and the remaining 461 were admitted for reasons unrelated to embolism (group II). In group I, 35 patients (32%) exhibited protruding plaques; those were fixed in 10 (9%) and with a mobile component in 25 (23%). In group II, plaques were found in only 13 patients (3%); fixed in 9 (2%) and mobile in 4 (1 %). Twenty-four patients with mobile lesions in group I were > 50 years old, and 21 of them (88%) were > 60 years old. While the presence of fixed plaques was associated with a moderate increase in the risk for systemic embolism (adjusted odds ratio 4.1; 95% confidence interval 1.3-56.4), mobile lesions were linked to a striking augmentation of this risk (odds ratio 30.1; 95% confidence interval 7.8-132.6). The majority of mobile lesions (76%) in group I represented disrupted atheromas with characteristic ulcerations or echolucency within the plaque suggestive of intraatheroma hemorrhage, whereas these TEE features were not observed in 89% of the mobile lesions in group II (p = 0.0003). We conclude that among the various types of mobile aortic lesions, the disrupted protruding plaques are a major risk factor for stroke and embolic events in the elderly.

Comparison of coronary calcium in stable angina pectoris and in first acute myocardial infarction utilizing double helical computerized tomography

Although coronary calcium is invariably associated with atherosclerosis, its role in the pathogenesis of acute and chronic coronary syndromes remains unclear. Utilizing double helical computerized tomography we evaluated the coronary calcium patterns in 149 patients: 47 with chronic stable angina (SAP) compared with 102 patients surviving a first acute myocardial infarction (AMI). Prevalence of coronary calcium was 81% among the AMI patients and 100% in the stable angina patients. The 547 calcific lesions identified in the AMI patients and the 1,242 lesions in the stable angina patients were categorized into 3 groups according to their extent: mild, intermediate, and extensive. The age-adjusted percentages of the highest level of calcification among AMI versus stable angina patients were: mild 18% vs 3%, intermediate 49% vs 18%, and extensive lesions 33% vs 79%, respectively (p < 0.01). In the AMI group, 73 culprit arteries were identified: 16 (22%) had no calcium detected, whereas 30 (41%) had mild lesions, 20 (27%) had intermediate forms, and only 7 (10%) had extensive lesions. The age-adjusted mean of the natural logarithm transformation of total calcium scores +1 was significantly lower in patients with AMI than in those with SAP (4.1 [95% confidence interval 3.7 to 4.4) vs 5.3 [95% confidence interval 4.8 to 5.8]). Thus, double helical computerized tomography demonstrates that extensive calcium characterizes the coronary arteries of patients with chronic stable angina, whereas a first AMI most often occurs in mildly calcified or noncalcified culprit arteries.

Coronary artery calcification in women with syndrome X: usefulness of double-helical CT for detection

PURPOSE

To determine the usefulness of double-helical computed tomography (CT) for detection of diseased coronary arteries in women with anginal pain, positive exercise stress test results, and angiographically normal coronary arteries (syndrome X).

MATERIALS AND METHODS

Double-helical CT of the coronary arteries was performed in 81 consecutive women who were referred for coronary angiography for evaluation of chest pain. Patients were classified into three groups according to stress test and angiographic results: normal (normal exercise test results and angiographically normal coronary arteries), syndrome X (abnormal exercise test results and angiographically normal coronary arteries), and coronary artery disease (at least one diseased vessel seen at angiography).

RESULTS

The prevalence of coronary calcification in the syndrome X group was 63% (10 of 16 patients) compared with 96% (45 of 47 patients) in the coronary artery disease group (P = .002) and 22% (four of 18 patients) in the normal group (P = .02). The lowest total coronary calcification score and logarithmic transformed data were found in the normal group (2.9 +/- 0.7), statistically significantly higher values were found in the syndrome X group (4.3 +/- 1.5), and the highest values were found in the coronary artery disease group (5.1 +/- 2.0; for trend, P = .03).

CONCLUSION

Double-helical CT may be useful in detection of atherosclerosis in women with syndrome X who demonstrate normal coronary arteries at angiography.

[Blunt trauma causing emboli from friable atherosclerotic plaques]

We present a 55-year-old woman who developed a shower of emboli following a car accident. Such events may have medicolegal implications as well as preventive considerations.

Coronary calcium measurements by double helical computed tomography. Using the average instead of peak density algorithm improves reproducibility

RATIONALE AND OBJECTIVES

Coronary calcium (CC) measured by fast computed tomography (CT) was proposed recently as a noninvasive method of monitoring the coronary atherosclerotic process. Assessment of the reproducibility of CC measurements (mainly interstudy variability) is essential for consistent interpretation of serial studies.

METHODS

The authors scanned 74 patients (50 men and 24 women) twice on the same day to determine the interstudy variability of a new scoring algorithm, using the average instead of conventional peak CT density values.

RESULTS

Nineteen patients had no calcium on either scan. In the remaining 55 patients, interstudy variability was decreased by 31% using the average algorithm (32%-23%; P < 0.001).

CONCLUSIONS

Using the average instead of conventional peak density score provides better reproducible measurements of calcium by double helical CT.

Does hormone replacement therapy inhibit coronary artery calcification?

OBJECTIVE

To determine the association between the use of hormone replacement therapy (HRT) and coronary calcium, in postmenopausal women who had no history of coronary artery disease by double helical computed tomography (CT).

METHODS

We used CT to compare the prevalence and extent of coronary calcium in 41 postmenopausal women who were on HRT from the first year of menopause and 37 age-matched controls who had never used HRT.

RESULTS

Both groups had a similar rate of smoking, hypertension, a positive family history, and hypercholesterolemia. Coronary calcification was observed in 28.2% of the 78 women studied. The prevalence of coronary calcium was significantly lower among HRT users: six of the 47 (14.6%), compared with 16 of the 37 nonusers (43.2%) (P < .01). The recorded risk factors had no effect on the prevalence of coronary calcium. Stepwise logistic regression analysis, including age, coronary risk factors, and HRT use as independent variables, yielded HRT as the only variable determining the presence of coronary calcium (odds ratio = 0.2; 95% confidence interval 0.06, 0.63; P = .006).

CONCLUSION

The lower incidence of coronary calcium in the HRT users suggests that HRT is associated with decreased prevalence of the coronary calcification.