Combined aortic and mitral balloon valvuloplasty in patients with critical aortic and mitral valve stenosis: results in six cases.

Six patients with severe combined aortic and mitral valve stenosis underwent double valve balloon dilation as an alternative to surgical valve replacement. Cardiac catheterization in all patients before valve dilation revealed heavily calcified aortic and mitral valves with severe stenosis and minimal regurgitation. Balloon aortic valvuloplasty was performed in each patient with a 20 mm balloon dilation catheter passed retrograde through the aortic valve whereas mitral valvuloplasty was performed transseptally with either a single or double balloon technique. After dilation, the mean aortic and mitral gradients decreased in all patients, with the area of the aortic and the mitral valve increasing from 0.5 +/- 0.3 to 0.9 +/- 0.3 cm2 and from 0.7 +/- 0.1 to 1.5 +/- 0.7 cm2, respectively. The procedures were well tolerated, with no embolic events and no significant increase in valvular regurgitation, and resulted in a reduction in symptoms of dyspnea on exertion and weakness in all patients that has persisted for an average of 5.7 months of follow-up in five of the six patients. It is concluded that combined dilation of stenotic aortic and mitral valves can be accomplished percutaneously and may be considered for patients with combined valvular stenosis who refuse or are deferred from surgical intervention.

The platelet estimate: is it being ignored?

A study was undertaken to determine whether the platelet estimate included in the routine CBC is being utilized as a guide to ordering quantitative platelet counts. Requisition slips and results were reviewed for a one-month period. The data showed that platelet estimates were not being used properly. In fact, much of the time the platelet count was being ordered with the CBC. The smear estimate and quantitative count agreed in 96% of specimens. The platelet count is a costly procedure and should be reserved for those occasions when the platelet estimate is abnormal.

Differences in alpha-adrenergic responsiveness between human internal mammary arteries and saphenous veins.

Little is known regarding specific biologic and pharmacologic differences between human internal mammary arteries and saphenous veins. To better define the role of alpha-adrenoceptor-mediated vasoconstriction in human internal mammary arteries and saphenous veins, we obtained fresh specimens of both vessels from 32 patients undergoing coronary artery bypass surgery. Dose-response curves were generated for the relatively selective alpha 1-receptor agonist phenylephrine, the alpha 2-receptor agonist BHT-920, and the alpha 1- and alpha 2-receptor agonist norepinephrine. Phenylephrine elicited similar contractile responses in internal mammary arteries and saphenous veins, with a mean EC50 (the effective concentration necessary to produce 50% of the maximal contraction) of 1.4 X 10(-6) M for internal mammary arteries and 1.8 X 10(-6) M for saphenous veins (p = NS). Selective stimulation of alpha 2-receptors with BHT-920 elicited a marked contractile response only in saphenous veins. Dose-response curves for phenylephrine and BHT-920 were shifted to the right for both vessels in the presence of the alpha 1-receptor antagonist prazosin and the alpha 2-receptor antagonist yohimbine, respectively. Norepinephrine elicited contraction at a lower concentration in saphenous veins than in internal mammary arteries with a mean EC50 of 7.8 X 10(-8) M for saphenous veins and a mean EC50 of 3.4 X 10(-7) M for internal mammary arteries (p less than 0.05). The results suggest that alpha-adrenoceptor-mediated vasoconstriction is caused primarily by alpha 1-receptors in human internal mammary arteries and by alpha 1- and alpha 2-receptors in human saphenous veins.

Salvage of branch vessels during bifurcation lesion angioplasty: acute and long-term follow-up.

To evaluate angiographic success, frequency of branch vessel loss and salvage, and long-term outcome, we studied the early and late outcomes of 56 consecutive patients who underwent PTCA of bifurcation lesions, which involved the left anterior descending or left circumflex coronary artery, with stenoses greater than 70% in both the parent and an involved branch vessel. In 35 patients (63%), the PTCA strategy was attempted dilation of both the main vessel and the involved branch vessels using predominantly a double-wire, sequential balloon technique; in 21 (27%) the PTCA attempt was confined to the main vessel alone. Transient angiographic occlusion of the branch vessel occurred in 32% of patients in whom dilation of both vessels was attempted, and in 38% in whom the main vessel alone was dilated (p = NS); 91% of the occluded branch vessels were the salvaged when sequential angioplasty of both vessels had been initially planned, compared to only 38% when the initial strategy had been dilation of the main vessel alone (p less than .05). Predischarge exercise testing showed residual ischemia in 6% of patients who had both vessels successfully dilated, versus 37% in those in whom dilatation was confined to the main vessels (p less than .01). Clinical restenosis, defined as late (greater than 6 weeks) recurrence of angina or a positive exercise test, occurred in 42% of patients who had both vessels successfully dilated. Thus although bifurcation lesion angioplasty frequently results in transient branch vessel loss, these branches can usually be salvaged using a double-wire technique but tend to have a higher late restenosis than conventional single vessel PTCA.

Epidemiology and natural history of hepatitis C infections in liver transplant recipients.

Hepatitis C infection is common in patients undergoing liver transplantation. Few studies have focused on the prevalence and epidemiology of hepatitis C infection among liver transplant recipients since the implementation of donor screening for antibodies against the hepatitis C virus (anti-HCV). Using reverse transcription-polymerase chain reaction (RT-PCR) and genomic sequencing methods, we sought to determine the prevalence, epidemiology, and natural history of hepatitis C infections among 44 consecutive liver transplant patients between January and December 1991. All patients and donors were screened for antibodies against HCV with a first-generation test. Laboratory tests and liver biopsies were routinely done 12 months after transplantation. Serum samples from all organ donors and transplant recipients were analyzed for the presence of HCV-RNA. From four of the six HCV-RNA-positive patients, pre- and post-transplant serum samples were available for sequence analysis. No donor had detectable HCV-RNA. Six of 44 (13.6%) patients had detectable HCV-RNA before and after liver transplantation. Recurrent infection was documented in all who were infected before transplantation and was confirmed by genotype analysis in the four patients who were analyzed. No acquired infections were identified. After transplantation, the HCV-RNA-positive recipients had higher mean alanine aminotransferase (207 +/- 85 U/l vs 37 +/- 7 U/l; p < 0.0001) and were more likely to have chronic hepatitis (50% vs 6%; p < 0.03) than the HCV-RNA-negative recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonic angioplasty in totally occluded peripheral arteries. Initial clinical, histological, and angiographic results.

BACKGROUND: Ultrasonic angioplasty was recently shown to ablate thrombi and atherosclerotic plaques in vitro and to recanalize occluded arteries in experimental animal models. The goal of the present study was to examine the clinical feasibility of ultrasonic angioplasty. METHODS AND RESULTS: Intraoperative ultrasonic angioplasty was performed in vivo on totally occluded peripheral arteries (n = 7). The ultrasonic angioplasty device consists of a 1.6-mm diameter flexible wire attached to a piezoelectric crystal generating ultrasound at 20 kHz. The controls, totally occluded human atherosclerotic femoral arterial segments (n = 6), were crossed mechanically with the ultrasound wire ex vivo but without application of ultrasonic energy. Ultrasonic angioplasty achieved successful recanalization without perforation in all vessels. Angiograms of the treated arteries showed an average lumen patency of 82.5%. Histological examination of the recanalized arteries revealed that the recanalization had taken place through intima diffusely involved with complicated plaque. The treated arteries, compared with the controls, had greater area of recanalized lumen (5.9 +/- 1.8 versus 1.7 +/- 0.4 mm2, p less than 0.05) and more flow (49.3 +/- 16.0 versus 11.8 +/- 4.9 ml/min, p less than 0.03). The damage in treated and control arteries was similar. Size-distribution analysis of the plaque debris from the treated arteries showed that 41 +/- 5% of the debris was 0.2-8 microns, 48 +/- 8% was 8-30 microns, and the remainder was 30-100 microns. In the mechanically crossed arteries, there was a shift in the distribution to larger size debris with 47 +/- 1% greater than 100 microns (p less than 0.001). CONCLUSIONS: Ultrasonic angioplasty may be a useful clinical method for recanalization of total occlusions in patients with peripheral vascular disease. Ultrasonic energy appears to cause controlled injury to the atherosclerotic intima by selectively disrupting the ultrasound-sensitive occlusion.

Progressive improvement in pulmonary vascular resistance after percutaneous mitral valvuloplasty.

Percutaneous mitral valvuloplasty has been proposed as a nonsurgical technique for treating high-risk patients with mitral stenosis who are deferred from mitral valve replacement. The effect of this technique on patients with pulmonary hypertension, however, has not been fully evaluated. Accordingly, serial assessment of pulmonary vascular resistance was made in 14 patients with critical mitral stenosis and pulmonary hypertension (pulmonary vascular resistance greater than 250 dynes.sec/cm5 or mean pulmonary artery pressure greater than 40 mm Hg or both) who underwent percutaneous balloon dilatation of the mitral valve. Balloon valvuloplasty was performed with either one (n = 10) or two (n = 4) balloons through the transseptal approach, and it resulted in significant improvement in mean mitral gradient (from 18 +/- 4 to 9 +/- 4 mm Hg, p less than 0.001), systemic blood flow (from 3.7 +/- 1.2 to 5.0 +/- 2.2 l/min, p less than 0.001), and calculated mitral valve area (from 0.7 +/- 0.2 to 1.6 +/- 0.7 cm2, p less than 0.001). Immediately after balloon mitral valvuloplasty, pulmonary vascular resistance fell from 630 +/- 570 to 447 +/- 324 dynes.sec/cm5. Repeat catheterization 7 +/- 4 months after valvuloplasty showed further improvement of pulmonary hypertension in 12 of the 14 patients, with a mean pulmonary vascular resistance for the group as a whole of 280 +/- 183 dynes.sec/cm5, p less than 0.005. In two patients, mitral valve restenosis to a mitral valve area less than 1.0 cm2 was associated with a return of pulmonary hypertension to predilatation values.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined percutaneous aortic valvuloplasty and transluminal coronary angioplasty in adult patients with calcific aortic stenosis and coronary artery disease.

Of 120 consecutive balloon aortic valvuloplasty procedures for critical aortic stenosis, valvuloplasty was performed in combination with coronary angioplasty in nine patients (average age 76 years). All nine patients were symptomatic with angina and congestive heart failure before combined procedures. Aortic valvuloplasty was performed with 20 to 23 mm balloon catheter advanced retrogradely from the femoral artery and resulted in an improvement in peak aortic valve gradient (60 +/- 19 to 33 +/- 13 mm Hg; p less than or equal to .01) and calculated aortic valve area (0.7 +/- 0.1 to 1.1 +/- 0.3 cm2; p less than or equal to .01). Single-vessel coronary angioplasty was performed via the femoral approach, with 2.0 to 3.5 mm balloon catheters, and resulted in a mean reduction of a critical coronary stenosis in each patient from 91 +/- 4% to 29 +/- 8%. The site of coronary angioplasty was the left anterior descending artery in three patients, the circumflex artery in three patients, the right coronary artery in two patients, and a bypass graft to the right coronary artery in one patient. Combined procedures were performed with a mean arterial time of 108 min. Complications included groin hematomas (n = 2), transient left bundle branch block (n = 1), and transient atrial fibrillation (n = 1). No patient experienced prolonged chest pain, myocardial infarction, major increase in aortic insufficiency, or embolic phenomena. Eight of the nine patients treated with combined procedures noted significant improvement in symptoms of angina and congestive heart failure and were discharged.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon aortic valvuloplasty in 170 consecutive patients.

Between October 1, 1985, and April 1, 1988, we performed balloon aortic valvuloplasty in 170 patients (mean age [+/- SD], 77 +/- 5 years) who had symptomatic aortic stenosis. The procedure was completed successfully in 168 patients and resulted in significant increases in the mean (+/- SD) aortic-valve area (from 0.6 +/- 0.2 to 0.9 +/- 0.3 cm2) and cardiac output (from 4.6 +/- 3.4 to 4.8 +/- 1.4 liters per minute) and decreases in the peak aortic-valve pressure gradient (from 71 +/- 20 to 36 +/- 14 mm Hg) (P less than 0.01 for all three comparisons). There were six in-hospital deaths, and five patients required early aortic-valve replacement. Follow-up data were available for all patients, for a period averaging 9.1 months. In addition to the 6 patients who died in the hospital, 25 patients died an average of 6.4 +/- 5.3 months after discharge. Symptoms recurred in 44 patients; they were managed by repeat valvuloplasty in 16 patients, by aortic-valve replacement in 17, and by medical therapy in 11. At the most recent follow-up examination, the symptoms of 103 patients had improved after valvuloplasty; this number includes 15 patients with restenosis who successfully underwent redilation. Life-table analysis indicates that the probability of survival 12 months after the procedure was 74 percent. We conclude that balloon aortic valvuloplasty is an effective palliative therapy for some elderly patients with symptomatic aortic stenosis. Symptoms improve in the majority of patients; although restenosis is common, it can be managed in some patients by repeat balloon dilation.