[The role of the echo-dipyridamole test in the diagnosis of coronary disease in patients with associated aortic stenosis]. / Il ruolo del test eco-dipiridamolo nella diagnosi di coronaropatia in pazienti con stenosi aortica associata.

BACKGROUND: Coronary vasodilator reserve is often significantly impaired in patients with aortic stenosis by several mechanisms: coronary artery disease, left ventricular hypertrophy, increase in cardiac chamber stiffness. The aim of this study was to evaluate the feasibility and the diagnostic accuracy of the dipyridamole echocardiography test in the diagnosis of coronary artery disease in patients with aortic stenosis. METHODS: Forty patients (26 males, 14 females, mean age 69 +/- 8.9 years) with aortic stenosis (mean valve area 0.7 +/- 0.3 cm2 calculated by the continuity equation) were studied by two-dimensional echocardiography during dipyridamole infusion up to 0.84 mg/kg over 10 min. Wall motion was graded for each segment as normal, hypokinetic, akinetic and dyskinetic. Dipyridamole echocardiography was considered positive for ischemia if wall motion in at least one segment worsened by at least one degree point level compared to wall motion at rest. All patients underwent coronary angiography (mean time after dipyridamole echocardiography 7 +/- 3 days). The chi 2 test and Student's t-test for paired data were used; a p value of < 0.05 was considered as statistically significant. RESULTS: Only one dipyridamole echocardiography was interrupted because of supraventricular tachycardia appearance. Nine patients showed new asynergy areas during dipyridamole echocardiography; 19 patients had ST segment downsloping of > or = 1 mm during dipyridamole infusion; 12 patients experienced angina during the test. Angiography showed a significant coronary stenosis in 10 patients. Dipyridamole echocardiography sensitivity was 80%, specificity was 96%; specificity of ST segment downsloping and angina were 63 and 76% respectively. CONCLUSIONS: Dipyridamole echocardiography in patients with aortic stenosis is safe and feasible with good sensitivity and better specificity. Our study suggests also that dipyridamole echocardiography test is able to rule out patients with aortic stenosis and coronary artery disease as opposed to those with angina without organic stenosis of the coronary vessels.

Novel clinical approaches in monoclonal antibody-based management in colorectal cancer patients: radioimmunoguided surgery and antigen augmentation.

Surgery, the most effective treatment for colon and rectal cancer, is based on empirical knowledge of the patterns of tumor spread, gross findings at laparotomy, and histologic confirmation of tumor-free margins. In spite of the many technical improvements in surgery, there has not been a significant change in cure rates for colon and rectal cancers. In fact, one-half of affected patients will not survive 5 years. It is in this arena of treatment for primary colon and rectal cancer patients that radioimmunoguided surgery (RIGS) technology may provide the most benefit. RIGS is an intraoperative procedure for detection of carcinoma lesions that are targeted with a radiolabeled monoclonal antibody (MAb) to provide the surgeon with immediate intraoperative definition of tumor margins and identification of occult disease. To optimize this technique, our studies were designed to increase tumor uptake by higher affinity CC-49 (a second-generation MAb) and to increase tumor antigen expression using biological response modifiers (BRMs). The ability of BRMs, such as interferons (IFNs), to enhance the expression of tumor-associated antigens, may play an important role in an adjuvant setting for MAb-based treatment. Preclinical and clinical data provided evidence for the use of IFN as an adjuvant to enhance MAb-targeting of human carcinoma lesions. A combination protocol with IFN and RIGS is ongoing at our institution.

Effect of acute and long-term administration of ramipril on circadian rhythm of blood pressure in essential hypertension.

Ambulatory monitoring was used to evaluate the antihypertensive efficacy and effect on circadian rhythms of blood pressure and heart rate of a single dose and long-term administration of ramipril in 20 patients with mild to moderate essential hypertension. Patients initially were randomized to receive either placebo or a single 5-mg dose of ramipril, followed 1 week later by 5 mg of ramipril daily for 6 months. Systolic (SBP) and diastolic blood pressure (DBP) and heart rate were measured every 20 minutes for 24 hours. Single-dose ramipril reduced both SBP and DBP (P < .001) without affecting heart rate. Long-term treatment produced a small additional antihypertensive effect, again without modifying heart rate. Cosinor analysis demonstrated that both administrations of ramipril effectively lowered SBP and DBP mesors (P < .001), compared to placebo; circadian rhythms remained undisturbed. Heart rate also was not modified on any circadian parameter. A significant reduction (P < .001) of blood pressure amplitude, however, occurred after long-term treatment and may have importance in terms of preventing cardiac damage.

Hepatitis C virus infection in thalassemia patients undergoing allogeneic bone marrow transplantation.

Ninety-eight patients with homozygous-beta thalassemia who had undergone allogeneic bone marrow transplantation (BMT) between May 1990 and March 1992 were tested for hepatitis C antibodies (anti-HCV) before and after BMT. Anti-HCV positivity was detected in 50 of the 98 patients (51%) before BMT. Seroconversion was demonstrated in seven of the 40 evaluable seronegative patients. In four cases it was probably due to the different sensitivity of first and second generation ELISA. Of the 46 evaluable seropositive patients 4 had transient and 5 persistent negativity for HCV antibodies after BMT. The high prevalence of anti-HCV positivity in thalassemic patients is related to the continuous requirement for blood transfusions. We found a strong correlation between biochemical and histological evidence of liver damage and anti-HCV positive status in multi-transfused patients. In our experience HCV hepatitis does not influence the outcome of BMT.

Acute and chronic nitrendipine administration in essential hypertension: a chronobiologic study.

To evaluate the chronobiologic pattern of the hypotensive effect of nitrendipine, 10 patients with mild-to-moderate arterial hypertension were studied. They received a randomized single dose (20 mg) of nitrendipine and placebo, and 20 mg of nitrendipine daily for 2 months. Systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data were analyzed by single and mean cosinor methods and by ANOVA and Student's paired t test. Chronic administration of nitrendipine resulted in a more effective lowering of the SBP and DBP mesor, compared with placebo and acute administration, preserving the circadian rhythms. The preservation of the HR circadian rhythm agrees with the lack of interference of the drug with neurohormonal mechanisms.

Circadian rhythm of blood pressure and calcium entry blockade: a chronobiologic study with nitrendipine in essential hypertension.

In order to evaluate the chronobiologic effect of nitrendipine, 27 patients with mild-to-moderate arterial essential hypertension were studied. After randomized administration of 20 mg of nitrendipine and placebo, systolic and diastolic blood pressure (SBP and DBP, respectively) and heart rate (HR) were measured for 24 h using an automatic noninvasive device. The data of the time series were statistically analyzed by single and mean cosinor methods (obtaining mesor, amplitude, and acrophase) and by ANOVA and Student's paired t test. Nitrendipine significantly reduced the SBP and DBP mesors without affecting the HR mesor, and reduced the SBP and DBP amplitudes while increasing the HR amplitude. After placebo, group circadian rhythms were observed for SBP, DBP, and HR and maintained after nitrendipine. In conclusion, a single-dose administration of nitrendipine is effective in lowering blood pressure. The increased HR amplitude is probably due to a tachycardic reaction. The preservation of the SBP, DBP, and HR group circadian rhythms agrees with the lack of interference of the drug with the neurohormonal mechanisms.