Transcatheter Aortic Valve Replacement in Degenerated Perceval Bioprosthesis: Clinical and Technical Aspects in 32 Cases

BACKGROUND

Sutureless aortic bioprostheses are increasingly being used to provide shorter cross-clamp time and facilitate minimally invasive aortic valve replacement. As the use of sutureless valves has increased over the past decade, we begin to encounter their degeneration. We describe clinical outcomes and technical aspects in patients with degenerated sutureless Perceval (CorCym, Italy) aortic bioprosthesis treated with valve-in-valve transcatheter aortic valve replacement (VIV-TAVR).

METHODS

Between March 2011 and March 2023, 1310 patients underwent aortic valve replacement (AVR) with Perceval bioprosthesis implantation. Severe bioprosthesis degeneration treated with VIV-TAVR occurred in 32 patients with a mean of 6.4 ± 1.9 years (range: 2-10 years) after first implantation. Mean EuroSCORE II was 9.5 ± 6.4% (range: 1.9-35.1%).

RESULTS

Thirty of thirty-two (94%) VIV-TAVR were performed via transfemoral and two (6%) via transapical approach. Vascular complications occurred in two patients (6%), and mean hospital stay was 4.6 ± 2.4 days. At mean follow-up of 16.7 ± 15.2 months (range: 1-50 months), survival was 100%, and mean transvalvular pressure gradient was 18.7 ± 5.3 mmHg.

CONCLUSION

VIV-TAVR is a useful option for degenerated Perceval and appears safe and effective. This procedure is associated with good clinical results and excellent hemodynamic performance in our largest single-center experience.

The Positive Impact of Early Frailty Levels on Mortality in Elderly Patients with Severe Aortic Stenosis Undergoing Transcatheter/Surgical Aortic Valve Replacement

Background: Frailty is highly common in older patients (pts) undergoing transcatheter aortic valve replacement (TAVR), and it is associated with poor outcomes. The selection of patients who can benefit from this procedure is necessary and challenging. The aim of the present study is to evaluate outcomes in older severe aortic valve stenosis (AS) pts, selected by a multidisciplinary approach for surgical, clinical, and geriatric risk and referred to treatment, according to frailty levels. Methods: A total of 109 pts (83 ± 5 years; females, 68%) with AS were classified by Fried's score in pre-frail, early frail, and frail and underwent surgical aortic valve replacement SAVR/TAVR, balloon aortic valvuloplasty, or medical therapy. We evaluated geriatric, clinical, and surgical features and detected periprocedural complications. The outcome was all-cause mortality. Results: Increasing frailty was associated with the worst clinical, surgical, geriatric conditions. By using Kaplan-Meier analysis, the survival rate was higher in pre-frail and TAVR groups (p < 0.001) (median follow-up = 20 months). By using the Cox regression model, frailty (p = 0.004), heart failure (p = 0.007), EF% (p = 0.043), albumin (p = 0.018) were associated with all-cause mortality. Conclusions: According to tailored frailty management, elderly AS pts with early frailty levels seem to be the most suitable candidates for TAVR/SAVR for positive outcomes because advanced frailty would make each treatment futile or palliative.

Female gender and mortality in ST-segment-elevation myocardial infarction treated with primary PCI

AIMS

To investigate gender difference in mortality among patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous angioplasty (PPCI).

METHODS

We analyzed data from the prospective registries of two hub PPCI centres over a 10-year period to assess the role of female gender as an independent predictor of both all-cause and cardiac death at 30 days and 1 year. To account for all confounding variables, a propensity score (PS)-adjusted multivariable Cox regression model and a PS-matched comparison between the male and female were used.

RESULTS

Among 4370 consecutive STEMI patients treated with PPCI at participating centres, 1188 (27.2%) were women. The survival rate at 30 days and 1 year were significantly lower in women (Log-rank P-value < 0.001). At PS-adjusted multivariable Cox regression analysis, female gender was independently associated with an increased risk of 30-day all-cause death [hazard ratio (HR) = 2.09; 95% confidence interval (CI): 1.45-3.01, P < 0.001], 30-day cardiac death (HR = 2.03;95% CI:1.41-2.93, P < 0.001), 1-year all-cause death (HR = 1.45; 95% CI:1.16-1.82, P < 0.001) and 1-year cardiac death (HR = 1.51; 95% CI:1.15-1.97, P < 0.001). For the study outcome, we found a significant interaction of gender with the multivessel disease in females who were at increased risk of mortality in comparison with men in absence of multivessel disease. After the PS matching procedure, a subset of 2074 patients were identified. Women still had a lower survival rate and survival free from cardiac death rate both at 30-day and at 1-year follow-up.

CONCLUSION

As compared with men, women with STEMI treated with PPCI have higher risk of both all-cause death and cardiac mortality at 30-day and 1-year follow-up.

Balloon Fracture During TAVR

An 88-year-old man was referred to transcatheter aortic valve replacement for severe symptomatic aortic stenosis. Edwards 26-mm Sapien bioprosthetic valve (Sapien) implantation was planned after accurate computed tomography–based procedure planning. When the valve was released, the inflation pressure decreased rapidly due to the balloon bursting. (Level of Difficulty: Advanced.)

1634 3D transoesofageal echocardiography in detection of anterior leaflet laceration during mitraclip implantation

Background

MitraClip is a percutaneous way of treatment of mitral regurgitation. Recent trials demonstrate its value in modifying prognosis of patients with functional mitral regurgitation. During MitraClip implant imaging with 3D TEE is mandatory to guide the procedure and monitoring the results. Unfortunately, laceration of mitral leaflets is a well-described complication of Percutaneous Mitral valve repair by implantation of MitraClip. 3D TEE can be useful even to detect complication of the procedure and in particular leaflets lacerations. Here we describe a case where 3D TEE was capable to recognize and visualize a laceration in the anterior leaflet (AL) and we assume some mechanisms leading to this complication.

Methods

An 83 years old man with post-ischemic severe functional mitral regurgitation underwent to MitraClip implantation. The mitral valve shows a severe tenting and annulus was deformed and dilated.

The procedure was performed under fluoroscopic and 3D TEE guidance (Philips iE33). Due to the large central regurgitation and large coaptation gap, we decide to implant MitraClip XTR, this is the larger device 5 mm longer.

Results

A single MitraClip XTR was implanted in the central scallop (A2-P2) in the region of the larger jet, after device positioning a further jet was detected in the region of implant and the original jet was unchanged.

Using 3D color complete volume and X-plane reconstructions we recognize that the jet originates between the clip and the basal aspects of AL. Without color Doppler in 3D zoom and X plane reconstruction, a continuum solution was suspected in the body of AL but the shadow of the delivery system partially masked the region. After removal of the device, perforation of AL was clearly depicted also with 3D zoom without color Doppler. The patient was surgically treated and inspection confirmed the laceration and shows a worn thin AL. The laceration of AL can be caused by the tension on a thinned tissue carried out by the large device. The severe tethering and annular dilatation with a marked distance between anterior and posterior leaflet at the tip of the device may have been a determinant factor in the tear occurrence.

Conclusion

3D TEE can clearly depict lacerations of leaflets during MitraClip implantation. Preoperative extensive analysis of valve geometry and inspection of leaflets searching for a thinned region can avoid intraoperative complications. The distance between leaflets at the expected tips of the MitraClip can be a predictive parameter of tension applied on the leaflets and of the risk of tearing.

Abstract 1634 Figure. Image 1

Usefulness of Triiodothyronine Replacement Therapy in Patients With ST Elevation Myocardial Infarction and Borderline/Reduced Triiodothyronine Levels (from the THIRST Study)

The aim of the study was to investigate whether TH replacement therapy is safe and impact infarct size, left ventricular (LV) volumes and function in patients with acute myocardial infarction (AMI) and low T3 syndrome (LT3S). Thirty-seven AMI/LT3S patients were randomly treated or untreated with liothyronine (T3) therapy (maximum dosage 15 mcg/m²/die) in addition to standardized treatment (T3-treated group, n = 19; untreated group, n = 18). TH and thyroxine (TSH) during hospital stay and at 1-month and 6 months were evaluated. At discharge and at 6 months LV volumes, ejection fraction, wall motion score index (WMSI) and infarct extent were measured by cardiac MR. T3-treated patients had a significant increase in fT3 (p = 0.003 and p <0.001) at discharge and 1-month. These patients had no signs or symptoms of hyperthyroidism or arrhythmias. At follow-up, there was a significant reduction in WMSI in both groups (T3-treated group: Δ = -0.12, p = 0.001; untreated group: Δ = -0.04, p = 0.04) and the difference value (discharge/follow-up) was significantly higher in T3-treated group than in untreated group (mean difference between groups = 0.08, 95% confidence interval [CI]: 0.01 to 0.15, p = 0.05). Also, stroke volume increased significantly in the T3-treated group (Δ = 3.4, 95% CI: 0.8 to 6, p <0.01) at follow-up. In conclusion, this is the first pilot experience in which T3 replacement therapy resulted safe and able to improve regional dysfunction in patients with STEMI/LT3S.

Development and validation of a risk stratification score for new-onset atrial fibrillation in STEMI patients undergoing primary percutaneous coronary intervention

AIM

New-onset atrial fibrillation (NOAF) is a complication not infrequent in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) and has been associated with worse in-hospital and long-term prognosis. We aimed to develop and validate a risk score based on common clinical risk factors and routine blood biomarkers to assess the early incidence of NOAF post-pPCI, before discharge.

METHODS

The risk score for NOAF occurrence during hospitalisation (about 5 days) was developed in a cohort of 1135 consecutive STEMI patients undergoing pPCI while was externally validated in a temporal cohort of 771 STEMI patients. Biomarkers and clinical variables significantly contributing to predicting NOAF were assessed by multivariate Cox-regression analysis.

RESULTS

Independent predictors of NOAF were age ≥80 years (6.97 [3.40-14.30], hazard ratio [95% CI], P < .001), leukocyte count > 9.68 × 10³ /μL (2.65 [1.57-4.48], P < .001), brain natriuretic peptide (BNP) > 80 ng/L (2.37 [1.13-4.95], P = .02) and obesity (2.07 [1.09-3.92], P = .03). By summing the hazard ratios of these predictors we derived the ALBO (acronym derived from: Age, Leucocyte, BNP and Obesity) risk score which yielded high C-statistics in both the derivation (0.734 [0.675-0.793], P < .001) and validation cohort (0.76 [0.688-0.831], P < .001). In both cohorts, using Kaplan-Meier risk analysis, the ALBO score identified a tertile of patients at highest risk (ALBO >4 points), with percentages of NOAF incidence of 30.8% and 27.4% in the derivation and validation cohort, respectively.

CONCLUSION

The ALBO risk score, comprising biomarkers and clinical variables that can be assessed in hospital setting, could help to identify high-risk patients for NOAF after pPCI so that a prompter action can be taken.

Left atrial appendage occlusion in high-risk patients with non-valvular atrial fibrillation

OBJECTIVE

Percutaneous left atrial appendage (LAA) occlusion has been developed as a viable option for stroke and thromboembolism prevention in patients with non-valvular atrial fibrillation (NVAF) and at high risk for cerebral cardioembolic events. Data on device implantation and long-term follow-up from large cohorts are limited.

METHODS

110 consecutive patients with NVAF and contraindications to oral anticoagulants (OACs) underwent LAA occlusion procedures and achieved a longer than 1 year follow-up. All patients were enrolled in a prospective registry. Procedures were performed using the Amplatzer Cardiac Plug or Amulet guided by fluoroscopy and intracardiac echocardiography.

RESULTS

Mean age of the population was 77±6 years old; 68 were men. Atrial fibrillation was paroxysmal in 20%, persistent in 15.5% and permanent in 64.5% of cases, respectively. Mean CHA₂DS₂-VASc and HAS-BLED scores were 4.3±1.3 and 3.4±1, respectively. Technical success (successful deployment and implantation of device) was achieved in 100% of procedures. Procedural success (technical success without major procedure-related complications) was achieved in 96.4%, with a 3.6% rate of major procedural complications (three cases of pericardial tamponade requiring drainage and one case of major bleeding). Mean follow-up was 30±12 months (264 patient-years). Annual rates for ischaemic stroke and for other thromboembolic events were respectively 2.2% and 0%, and annual rate for major bleeding was 1.1%.

CONCLUSIONS

Our data suggest LAA occlusion in high-risk patients with NVAF not suitable for OACs is feasible and associated with low complication rates as well as low rates of stroke and major bleeding at long-term follow-up.

[Venous graft in-stent restanosis: diagnostic and treatment evolution]

This is the case of a 77 year-old man with previous coronary by-pass grafting. After the occlusion of the saphenous vein graft to marginal branch, corrected by angioplasty and stenting with a bare metal stent (BMS), during the next 4 years he experienced multiple further episodes of in-stent restenosis of the first BMS. Angioplasty was performed each time. After 4 months since the last procedure, he had new episode of unstable angina. An EKG-gated, 64-row multislice CT (MSCT) examination was performed to evaluate the venous graft lumen, showing high-grade in-stent restenosis. Angiography confirmed the MSCT diagnosis, thus he underwent angioplasty and stenting with a drug eluting stent (DES). Thereafter, he remained stable for 4 years, when new anginal episodes led to a further coronary angiogram, showing progression of the atherosclerosic disease at the proximal and distal anastomosis of the venous graft; however, the previous implanted DES was patent. In the complex management of venous grafts restenosis, MSCT can be useful to help in detecting obstructive bypass graft disease. When revascularization is needed, DES have shown to be superior compared to BMS.

Endovascular treatment of acute thoracic aortic syndromes with a proximal landing zone extension strategy: procedural and follow-up results

PURPOSE

To report the procedural and long-term follow-up data (mean, 43 ± 29 months; range, 12-90 months) of endovascular stent grafting (ESG) of acute thoracic aortic syndromes (ATAS) with a proximal landing zone extension strategy.

METHODS

From November 1999 to May 2008, 26 patients (25 males, 1 female; mean age, 57.9 ± 17 years) with ATAS underwent ESG at our institution. Underlying pathologies were: penetrating aortic ulcer (n=7); rupture of a descending aorta aneurysm (n=5), post-traumatic false aneurysm (n=5); acute type B dissection (n=6) and traumatic descending aorta transection (n=3).

RESULTS

ESG was performed successfully in all patients. In 5 patients (19%), an extra-anatomic revascularization of the supra-aortic vessels was performed. In 19 patients (73%), overstenting of the left subclavian artery, without preliminary revascularization, was performed. The mean proximal landing zone length was 57 ± 19 mm. No intraprocedural deaths occurred; 3 patients died postoperatively (1 from an unrelated cause, 1 from a myocardial infarction and 1 for the sequelae of an ischemic stroke). One patient underwent cardiac surgery for post-procedural retrograde type-A dissection. Follow up involved a computed tomography (CT) scan at 1, 3, 6 and 12 months, then yearly thereafter. At follow up, no deaths or major complications occurred. The CT scans revealed 1 small type-IB endoleak at 1 year.

CONCLUSION

In ATAS patients treated with ESG, the extension of the proximal landing zone, despite the need of subclavian coverage or hybrid procedures, is associated with an immediate procedural outcome and low morbidity at follow-up.

[Door-to-balloon time and in-hospital mortality in patients with ST-evaluation myocardial infarction: a network experience in a province in northwest Tuscany, Italy]

BACKGROUND

A network system for ST-elevation myocardial infarction (STEMI) patients offers a quick diagnosis and a rapid transfer to a specialized center for primary percutaneous coronary intervention. The aim of our study was to evaluate the relationship between door-to-balloon time and in-hospital mortality in our network of STEMI patients.

METHODS

Our Hub & Spoke network in the province of Massa-Carrara in the northwest of Tuscany Region, Italy, began in April 2006. This program involved 5 Spoke and 1 Hub centers, 1 medical helicopter, 3 advanced life support ambulances with direct transmission of the ECG and vital parameters to our cath lab on call 24h a day for primary percutaneous coronary intervention. Data regarding clinical, echocardiographic and hemodynamic parameters, the door-to-balloon (DTB) time and their impact on mortality were analyzed.

RESULTS

Up to January 2008, 312 STEMI patients were enrolled (242 male, mean age 66.6 +/- 12.3 years). The DTB time was 93 min (79-117, 25th-75th percentile, respectively). The gold standard of a DTB < or = 90 min was reached in 47.1% of patients. In-hospital mortality was associated with a longer DTB time as compared to alive patients (92 vs 120 min, p < 0.03). Two geographic areas of our territory were considered: the coast and the mountain area. Patients from the coast (n = 238) had a DTB time lower than patients from the mountain area (89.5 vs 122.5 min, p < 0.0001), and the risk of in-hospital mortality was significantly and independently correlated with the increase in DTB time (p = 0.04). CONCLUSIONS; Our data confirm the correlation between DTB time and in-hospital mortality. More efforts are necessary to reduce the time to treatment and mortality rates.

Drug-eluting stents versus bare-metal stents in acute ST-segment elevation myocardial infarction. a single-center experience with long-term follow up

OBJECTIVES

To compare the efficacy and safety of drugeluting stents (DES) vs. bare-metal stents (BMS) in patients with acute ST-segment-elevation myocardial infarction (STEMI).

BACKGROUND

DES effectively reduce restenosis in elective percutaneous coronary intervention. Limited data are available about the use of DES in patients with STEMI.

METHODS

453 consecutive patients who presented with STEMI between July 2003 and May 2006 were studied. The procedural characteristics, 30-day, 12-, 18- and 26-month outcomes of 277 patients treated with DES were compared with 176 patients treated with BMS.

RESULTS

At 26-month follow up, DES therapy was associated with a significant decrease in major adverse cardiac events (MACE) (relative risk [RR] -35%; p = 0.01) and target lesion revascularization [TLR], RR -64%; p = 0.009). The DES group included more diabetic patients (20% vs. 9%; p < 0.001), and the stents were longer (22 +/- 0.28 mm vs. 19.4 +/- 0.36 mm; p < 0.001) and smaller (diameter: 2.9 +/- 0.02 mm vs. 3.1 +/- 0.02 mm; p < 0.001). The rate of stent thrombosis was similar and the prolonged combined antiplatelet therapy was an independent factor predicting a protective effect on MACE.

CONCLUSIONS

DES reduce the incidence of TLR and MACE in patients with STEMI without evidence of additional risks at 2-year follow up. DES therapy was associated with more complex interventional techniques, which yielded similar procedural results and clinical outcomes that may be influenced by prolonged combined antiplatelet therapy.

Influence of involvement of anterior leaflet versus posterior leaflet on residual regurgitation as assessed by transesophageal echocardiography in patients undergoing valve repair for mitral regurgitation due to mitral valve prolapse

Background

Repair of anterior leaflet prolapse is technically more challenging and this might influence outcomes as compared to the repair of posterior leaflet prolapse in patients undergoing surgical correction of mitral regurgitation. We investigated the association of anterior leaflet prolapse with minor residual mitral regurgitation (MR) in patients with mitral valve prolapse (MVP) who underwent valve repair.

Methods

Eligible for this study were consecutive patients with severe MR due to MVP, who underwent mitral valve repair with residual MR by postpump transesophageal echocardiography ≤2+ during a 20-month period at Pasquinucci Hospital, Massa. Patients undergoing other cardiovascular surgical interventions were excluded. Two groups were defined according to the involvement of mitral valve leaflets: group 1, consisting of patients with anterior leaflet prolapse (isolated or not); and group 2, consisting of patients with isolated posterior leaflet prolapse.

Results

A total of 70 patients (18 in group 1 and 52 in group 2) were analyzed. Patients in group 2 were younger than those in group 1, but the difference was not significant (P = 0.052). There were no significant differences between the 2 study groups with respect to other variables. The proportion of patients with residual MR 1+/2+ was higher in group 1 than in group 2 (61.1% vs. 32.7%, respectively; P = 0.034). In a logistic regression model, anterior leaflet prolapse was an independent predictor of residual MR 1+/2+ (odds ratio, 4.0; 95% confidence interval, 1.14 to 14.04; P = 0.03).

Conclusion

In our study population, patients with anterior leaflet prolapse had a higher proportion of residual MR 1+/2+ as compared to those with posterior leaflet prolapse after repair of mitral valve.

The impact of a school-based safe water and hygiene programme on knowledge and practices of students and their parents: Nyanza Province, western Kenya, 2006

Safe drinking water and hygiene are essential to reducing Kenya's diarrhoeal disease burden. A school-based safe water and hygiene intervention in Kenya was evaluated to assess its impact on students' knowledge and parents' adoption of safe water and hygiene practices. We surveyed 390 students from nine schools and their parents at baseline and conducted a final evaluation of 363 students and their parents. From baseline to final evaluation, improvement was seen in students' knowledge of correct water treatment procedure (21-65%, P<0.01) and knowing when to wash their hands. At final evaluation, 14% of parents reported currently treating their water, compared with 6% at baseline (P<0.01). From 2004 to 2005, school absenteeism in the September-November term decreased in nine project schools by 35% and increased in nine neighbouring comparison schools by 5%. This novel programme shows promise for reducing school absenteeism and promoting water and hygiene interventions in the home.

An increased platelet–leukocytes interaction at the culprit site of coronary artery occlusion in acute myocardial infarction: A pathogenic role for “no-reflow” phenomenon?

BACKGROUND

Distal protection devices have been shown to reduce the incidence of "no flow" phenomenon during primary percutaneous coronary intervention (PCI). So far, it has not been well clarified which mechanism is mainly involved in distal coronary protection.

AIM

To investigate the activation state of leukocytes and platelets locally present within the blood from the site of coronary occlusion.

METHODS

Ten patients with acute myocardial infarction (AMI) underwent primary PCI with an embolization protection device and aspiration catheter (PercuSurge GuardWire) were included. The following functional parameters: a) monocyte and neutrophils surface molecules; b) platelet surface activatory antigens; c) leukocytes-platelet conjugates were studied by flow cytometry in blood obtained from the site of coronary occlusion and from peripheral femoral artery.

RESULTS

The leukocyte-platelet adhesion index was significantly higher in the aspirated blood at the site of coronary occlusion than in the peripheral arterial blood for both monocytes (0.226+/-0.04 vs. 0.084+/-0.01; p=0.004) and neutrophils (1.372+/-0.3 vs. 0.524+/-0.1; p=0.02). Moreover, the volume of coaggregates exhibited a significant increase in coronary blood for both populations (p=0.02 for monocytes and for neutrophils). Interestingly, a significant up-regulation of the adhesive molecule CD18 was observed in coronary blood respect to systemic circulation either in monocytes (p=0.01) than in neutrophils (p=0.003). A significant up-regulation of monocyte (HLA-DR) and neutrophil (CD66b) activatory molecules expression was also observed in the aspirated coronary compared to peripheral artery blood (p=0.02 and p=0.03 for HLA-DR and CD66b, respectively).

CONCLUSIONS

These data indicate an increased leukocyte-platelet functional interaction in AMI at the site of plaque rupture relative to the systemic circulation, which may be one of the pathogenetic mechanisms responsible for myocardial "no-reflow" phenomenon.

Atrial natriuretic peptide is not degraded by the lungs in humans

In an attempt to identify and quantify the sites of atrial natriuretic peptide (ANP) degradation, particularly the lungs, a new tracer method to study ANP metabolism in vivo in humans was developed and applied to patients with left ventricular dysfunction. Thirteen male, normotensive, cardiac patients with different degrees of left ventricular myocardial involvement were enrolled in the study. The study protocol required constant infusion (3 patients) or bolus injection (10 patients) of 125I-labeled ANP just upstream of the right atrium and blood sampling from different sites (pulmonary artery, aorta, inferior vena cava, and femoral vein) during the hemodynamic study. Data analysis was based on a kinetic model consisting of three blocks in series (right heart, lungs and left heart, and periphery) supplied by the same plasma flow (plasma cardiac output). Plasma levels of native ANP were measured with a sensitive and specific immunoradiometric assay method. ANP values measured in the aorta (163.9 +/- 144.8 pg/mL, n = 80) were superimposable on those measured in the pulmonary artery (161.8 +/- 136.5 pg/mL, n = 80). Negligible extraction of 125I-labeled ANP was found in the lungs and left heart block (on average 0.08 +/- 3.92%), whereas the peripheral block extraction (46.2 +/- 7.8%) accounted for almost total hormone removal from the blood (whole body extraction was 46.4 +/- 6.6%). ANP metabolic clearance rate (3.11 +/- 1.48, range 1.4-6.8 L/min) declined with the progression of left ventricular dysfunction (plasma cardiac output 3.46 +/- 1.08, range 1.2-5.7 L/min), and a close correlation between metabolic clearance rate and cardiac output was evident. Our data suggest that lungs do not extract, or extract only very small amounts, of labeled ANP administered iv to patients with different degrees of left ventricular myocardial involvement, and whole body extraction of labeled ANP remains relatively stable with the progression of disease, and the large reductions in clearance values observed in our patients can be ascribed mainly to the reductions in cardiac output.

Acute hemodynamic effects of endogenous adenosine in patients with chronic heart failure

OBJECTIVE

The objective of this study was to assess the acute hemodynamic effects of endogenous adenosine accumulation in patients with chronic heart failure. Exogenously administered adenosine has been shown to reduce pulmonary vascular resistance and to increase cardiac index in normal subjects and in patients with pulmonary hypertension or end-stage biventricular heart failure. Endogenous adenosine accumulation can be provoked by dipyridamole.

METHODS AND RESULTS

Ultra-low-dose dipyridamole (0.07 mg/kg/min for 4 minutes) was administered in 20 patients with either symptomatic idiopathic (n = 12) or ischemic (n = 8) dilated cardiomyopathy and reduced left ventricular ejection fraction (mean 25%+/-5%). Hemodynamic variables were measured before and within 1 minute from the end of dipyridamole infusion. After dipyridamole administration, a mild but significant increase in heart rate (4.5%; p = 0.03) and reduction in mean blood pressure (6.8%; p < 0.001) without changes in right atrial pressure (p = NS) were detected. Dipyridamole increased cardiac output by 26.6% (p < 0.001), cardiac index by 24% (p < 0.001), and stroke volume by 19.8% (p < 0.001), with concomitant 24.6% reduction of systemic vascular resistance (p < 0.001). Moreover, dipyridamole reduced mean pulmonary artery pressure by 8.3% (p < 0.01) and pulmonary vascular resistance by 33.3% (p = 0.001), without changes in pulmonary wedge pressure (p = NS). A significant correlation between percent decrease from baseline in pulmonary and systemic vascular resistance (r = 0.66; p = 0.002) was found after administration of dipyridamole.

CONCLUSIONS

Endogenous adenosine accumulation induced by ultra-low-dose dipyridamole infusion acutely improves the hemodynamic profile, decreasing pulmonary and, to a lower extent, systemic vascular resistance and increasing cardiac index in patients with severe chronic heart failure.

Evidence that atrial natriuretic peptide tissue extraction is not changed by large increases in its plasma levels induced by pacing in humans

Atrial natiurectic peptide (ANP) is a cardiac hormone with a very short plasma half-life, which plays an important role in a variety of clinical conditions associated with an increase in pressure and/or volume overload on the heart. The MCR of the hormone is considered to represent a stable parameter, reflecting the uptake and degradation rate of ANP by the periphery, only scarcely affected by rapid oscillations of circulating levels. To evaluate the extent to which MCR is affected by rapid and large variations of circulating levels of the hormone, we measured MCR in five patients with different degrees of myocardial function (from normal to severely impaired), in whom changes in ANP levels were induced by atrial and/or ventricular pacing. Cardiac output was simultaneously measured by thermodilution to calculate whole body extraction of ANP. During constant i.v. infusion of [125I]ANP, the hormone MCR was determined both under basal conditions (at tracer equilibration, 20-30 min after the start of infusion) and during atrial and ventricular pacing. Pacing maneuvers, begun 50 min after the start of infusion, induced a marked and rapid increase in endogenous plasma ANP values in all patients (on the average, 3,7-fold compared to basal values; range, 1.8-5.68), whereas corresponding values of [125I]ANP only minimally changed. The MCR of ANP (3.62 +/- 1.06 L/min, mean +/- SD) slightly decreased (by repeated measures ANOVA, P = 0.0458) during atrial and ventricular pacing procedures (3.35 +/- 1.03 and 3.15 +/- 0.74 L/min, respectively), reaching a mean value of 88.7 +/- 9.0% compared to basal. The small decrease in MCR could be almost completely ascribed to hemodynamic factors; indeed, basal cardiac output (5.76 +/- 1.70 L/min) was found, on the average, to be slightly decreased during atrial and ventricular pacing (5.28 +/- 1.46 and 5.16 +/- 1.33 L/min, respectively), and so whole body extraction of the hormone, measured before pacing (50.0 +/- 12%), remains stable throughout the study period (50.4 +/- 10.6% and 49.6 +/- 10% during atrial and ventricular pacing, respectively). Our findings demonstrate that degradative mechanisms involved in ANP clearance are not saturable at least for acute elevations of ANP plasma levels up to 3-5 times the basal level.

Acute effects of amiodarone administration on thyroid function in patients with cardiac arrhythmia

Because little has been published on early effects of treatment with amiodarone on thyroid function, we studied serum total and free thyroid hormone, reverse T3, and TSH levels in patients with cardiac arrhythmias during the first 10 days of treatment with a loading dose of amiodarone by iv infusion. Twenty-four patients were enrolled in the study. A standardized loading regimen for the i.v. infusion of amiodarone was used. The protocol provided the i.v. infusion of 20 mg/kg per day on day 1, the i.v. infusion of 10 mg/kg per day on day 2, then 600 mg/day per os for 7-10 days, and finally, in patients chronically treated with the drug, the dose was gradually reduced to 400-200 mg/day per os. Total and free concentrations of T4 tended to progressively and significantly increase (P < 0.0001 repeated measures ANOVA) starting from the fourth day of therapy, whereas total T3 decreased from the second day progressively (P < 0.0001) throughout the study; free T3 did not significantly change. TSH levels early and significantly (P < 0.001, by ANOVA) increased throughout the study, starting from the first day of therapy and reaching at 10 days a value 2.7 times higher than the basal value. Reverse T3 levels progressively and significantly (after 2 days of treatment) increased and paralleled the TSH values, reaching at the 10th day a value about 2 times higher than basal value. In conclusion, our data suggest that after i.v. treatment with amiodarone: 1) TSH is the first hormone to change significantly followed by reverse T3, T4, and T3; 2) the progressive fall of T3 levels reflects an inhibition of the peripheral conversion of T4 to T3; 3) the observed later increase of total and free T4 levels may be explained by a contribution of direct thyroidal stimulation by TSH and/or by a reduction in T4 clearance.

Acute enoximone effect on systemic and renal hemodynamics in patients with heart failure

Patients with heart failure generally show improvement in their clinical condition after enoximone infusion over the period of treatment; this effect cannot be ascribed only to the known hemodynamic action of this drug. Thirty-six patients (age range 44-82 years) with heart failure (NYHA class II-IV) underwent 48-hour enoximone infusion to study whether this prolonged improvement might depend on changes in systemic or renal hemodynamics or in neurohormonal balance. All patients underwent Swan-Ganz hemodynamic monitoring; renal plasma flow, glomerular filtration rate, plasma atrial natriuretic factor (ANF), and plasma renin activity (PRA) were all measured at baseline, at the peak of the enoximone action, and 48 hours after drug discontinuation. The main hemodynamic parameters were significantly improved during enoximone infusion and after drug discontinuation. The cardiac index basal value of 2.2 +/- 0.1 l/min/m2 increased to 3.1 +/- 0.1 l/min/m2 after 24-hour therapy (p < 0.01); similarly, pulmonary wedge pressure, mean pulmonary arterial pressure, and right atrial pressure decreased markedly (p < 0.01). Beneficial effects were also observed in renal hemodynamics; indeed, renal plasma flow (basal value 485 +/- 39 ml/min) increased significantly after 24-hour enoximone infusion (575 +/- 35 ml/min; p < 0.01), and this tendency was also observed 48 hours after drug discontinuation. No significant modifications were observed in plasma hormone data; however, the PRA plasma level had a tendency to decrease. We conclude that in patients with heart failure, enoximone infusion has a less marked effect on renal hemodynamics, but this is more lasting than systemic hemodynamic effects. The tendency of PRA to decrease (although not statistically significant), still detectable 2 days after treatment in the presence of steady high plasma ANF concentrations, may also contribute to the paradoxical longlasting benefit despite the short-lived improvement in systemic hemodynamics after brief cycles of enoximone infusion.