Effect of balloon mitral valvuloplasty on exercise capacity, ventilation and skeletal muscle oxygenation

OBJECTIVES

The short- and long-term effects of valvuloplasty on exercise capacity, ventilation and skeletal muscle oxygenation were investigated to determine whether a dissociation between hemodynamic improvement and exercise capacity occurs in patients with mitral stenosis.

BACKGROUND

Percutaneous balloon mitral valvuloplasty in patients with mitral stenosis results in immediate hemodynamic improvement at rest and with exercise. Improved exercise capacity has been described at 3 months after valvuloplasty. In patients with left ventricular dysfunction, acute therapeutic interventions that produce hemodynamic benefit do not immediately improve exercise capacity.

METHODS

Maximal bicycle exercise with measurement of respiratory gases was performed in 11 patients with mitral stenosis before and at 48 h and 3 months after successful percutaneous balloon mitral valvuloplasty. Respiratory and leg skeletal muscle oxygenation were assessed by monitoring changes in light absorption of the serratus anterior and vastus lateralis muscles using near-infrared spectroscopy and were expressed as percent deoxygenation.

RESULTS

Mitral valvuloplasty significantly increased mean mitral valve area from 1.0 +/- 0.2 to 1.7 +/- 0.3 cm2 (p < 0.05). Immediately after valvuloplasty, peak exercise oxygen consumption (VO2), VO2 at the anaerobic threshold, ventilation, peak respiratory and leg muscle deoxygenation all remained unchanged. At submaximal work loads, respiratory muscle deoxygenation was attenuated (25 W: before 12 +/- 4%; 48 h 4 +/- 3%; 50 W: before 10 +/- 5%; 48 h 5 +/- 4%; both p < 0.05). At 3 months, significant improvement in peak VO2 (before 10.9 +/- 5%; 3 months 14.6 +/- 6.2 ml/kg per min; p < 0.05) and VO2 at the anaerobic threshold (before 7.1 +/- 2.4; 3 months 8.4 +/- 2.3; p < 0.05) were observed, whereas ventilation remained unchanged. No further improvement was seen in respiratory muscle deoxygenation. Vastus lateralis deoxygenation at submaximal work loads tended to be decreased.

CONCLUSIONS

Long-term changes in skeletal muscle and the lungs preclude immediate enhancement of exercise performance after balloon mitral valvuloplasty. Immediate symptomatic improvement probably results from an immediate decrease in the work of breathing. Long-term symptomatic improvement results from changes that occur in the peripheral skeletal musculature as well as from the reduced work of breathing.

Effect of balloon size and stepwise inflation technique on the acute results of Inoue mitral commissurotomy. Inoue Balloon Catheter Investigators

Currently percutaneous transvenous mitral commissurotomy (PTMC) is performed by most operators using stepwise inflation of the Inoue balloon beginning at a small diameter and increasing size by a sequence of inflations to nominal diameter. The effect of balloon size on procedure results using the Inoue balloon has not been evaluated. In 260 patients final balloon inflation was to nominal size in 42% of pts, larger than nominal size (overinflated) in 10%, and less than nominal size (underinflated) in 48% of pts. The average number of inflations was 3 (range 1-9). Pressure gradient and Doppler mitral regurgitation (MR) were assessed after each inflation. When MR increased, further inflations were not done. Patients in whom the balloon was overinflated underwent more balloon inflations than those in whom it was inflated to nominal size (5.0 +/- 2.1 vs. 2.9 +/- 1.4, p < 0.01). Those with balloon underinflation had fewer balloon inflations (2.4 +/- 1.2 vs. 2.9 +/- 1.4, p < 0.01). The post PTMC valve area in patients with overinflation was slightly less than those with nominal inflations (1.6 +/- 0.4 vs. 1.8 +/- 0.7), and with underinflation the valve area was no different compared to nominal inflation. Using a stepwise procedure, if mitral regurgitation was noted to increase after a balloon inflation, the procedure would be stopped even if less than an ideal result was achieved. Fewer inflations were done in patients in whom the balloon was inflated to less than nominal size because of the appearance of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term outcome of enoximone therapy in patients with refractory heart failure

Few options are available for patients with severe heart failure that is unresponsive to therapy with digoxin, diuretics, and vasodilators. The clinical responses and predictors of survival were studied in 41 consecutive patients with New York Heart Association (NYHA) class IV heart failure during long-term oral enoximone therapy (mean dose 232 +/- 15 mg/day). The mean age was 60 +/- 1 years, and the initial left ventricular ejection fraction was 0.19 +/- 0.01. The cause of heart failure was either coronary artery disease (n = 23) or dilated cardiomyopathy (n = 18). Symptomatic improvement occurred in the majority (83%) of patients; 24% improved two or more NYHA classes. Although the 12-month mortality rate for the entire group was high (54 +/- 8%), a subgroup of patients with dilated cardiomyopathy achieved a sustained benefit with a decrease in symptoms > 1 NYHA class, fewer hospitalizations, and a survival rate at 24 months of 60%. Multivariate analysis identified the cause of heart failure, left ventricular ejection fraction, and clinical improvement within 60 days of enoximone therapy as predictors of a favorable long-term outcome. The presence of coronary artery disease was most predictive of early mortality (p < 0.0002), with only 5% of patients surviving > 18 months compared to 66% of those with dilated cardiomyopathy. Median survival rates were 132 +/- 31 and 921 +/- 214 days (p < 0.001) for the coronary artery disease and dilated cardiomyopathy populations, respectively. Oral enoximone can provide symptomatic improvement and a palliative option for the majority of patients with refractory heart failure resulting from cardiomyopathy.

Percutaneous balloon pericardiotomy for the treatment of cardiac tamponade and large pericardial effusions: description of technique and report of the first 50 cases

OBJECTIVES

This study describes the technique, clinical characteristics and results of the first 50 patients undergoing percutaneous balloon pericardiotomy as part of a multicenter registry.

BACKGROUND

Percutaneous balloon pericardiotomy involves the use of a percutaneous balloon dilating catheter to create a nonsurgical pericardial window.

METHODS

Patients eligible for percutaneous balloon pericardiotomy had either cardiac tamponade (n = 36) or a moderate to large pericardial effusion (n = 14). In addition to clinical follow-up, serial echocardiograms and chest X-ray films were obtained.

RESULTS

The procedure was considered successful in 46 patients after a mean follow-up period of 3.6 +/- 3.3 months. Two patients required an early operation, one for bleeding from a pericardial vessel and one for persistent pericardial catheter drainage. Two patients required a late operation for recurrent tamponade. Minor complications of the procedure included fever in 6 of the first 37 patients (studied before the prophylactic use of antibiotic agents), thoracentesis or chest tube placement in 8 and a small spontaneously resolving pneumothorax in 2. Despite the short-term success of this procedure, the long-term prognosis of the 44 patients with malignant pericardial disease remained poor (mean survival time 3.3 +/- 3.1 months).

CONCLUSIONS

Percutaneous balloon pericardiotomy is successful in helping to manage large pericardial effusions, particularly in patients with a malignant condition. It may become the preferred treatment to avoid a more invasive procedure for patients with pericardial effusion and a limited life expectancy.

Failure of endocardial biopsy from the internal jugular vein due to endocardial scar: a new indication for the femoral venous approach

Following cardiac transplantation, patients undergo serial endomyocardial biopsies to evaluate rejection, usually by the internal jugular approach. A case report and data are presented that demonstrate that this approach becomes less efficient and occasionally impossible in the third year after transplant (53% success rate per biopsy attempt) as compared to the first year after transplant (80%) probably due to the development of endocardial scar in the area sampled by the bioptome. Alternatively, one can change to the femoral venous approach which continues to have a high success rate in the third year after transplant (83%) because a different area of the interventricular septum is sampled when this approach is used.

Effects of pacing tachycardia and balloon valvuloplasty on pulmonary artery impedance and hydraulic power in mitral stenosis

BACKGROUND

Mitral stenosis is characterized by progressive pulmonary hypertension and eventual right ventricular failure. However, the correlation between right ventricular failure and the level of pulmonary hypertension is poor, suggesting that factors other than those recognized from nonpulsatile hemodynamic parameters may contribute to impaired right ventricular performance in this condition.

METHODS AND RESULTS

We studied 16 patients with severe mitral stenosis (mean valve area, 1.0 +/- 0.2 cm2) at supine rest and during pacing tachycardia using high-fidelity catheter recordings of pulmonary artery (PA) pressure and flow velocity. Pulmonary impedance spectra, wave reflection properties, and hydraulic power data were derived from Fourier analysis of signal-averaged data. Pacing tachycardia (baseline heart rate, 81 +/- 11 beats per minute; pacing, 132 +/- 11 beats per minute) significantly raised pulmonary wedge and mean PA pressures. There was no change in pulmonary vascular resistance (209 +/- 144 to 232 +/- 164 dyne-sec/cm5) or PA characteristic impedance (62 +/- 25 to 55 +/- 28 dyne-sec/cm5). However, first harmonic impedance (Z1) significantly decreased (134 +/- 71 to 100 +/- 68 dyne-sec/cm5; p < 0.001). Accordingly, oscillatory and total dissipated hydraulic power per unit forward flow (WT/CO) fell during tachycardia (2.6 +/- 1.6 to 2.3 +/- 1.4 mW/ml.sec-1; p = 0.06) despite acute pulmonary hypertension. Reflected pressure waves returned earlier to the proximal PA, suggesting increased vessel stiffness. Immediately after percutaneous balloon mitral valvuloplasty (PBV) in eight of the patients, baseline and pacing data were again recorded. Compared with the pre-PBV baseline state, post-PBV resting data demonstrated no change in resistance or characteristic impedance, but there was a significant fall in Z1 (166 +/- 75 to 103 +/- 45 dyne-sec/cm5; p < 0.05) and in the magnitude of pulmonary wave reflections. WT/CO tended to decrease after PBV, and pacing after PBV produced a further decrease in WT/CO, again in association with lower Z1.

CONCLUSIONS

These data demonstrate that 1) increased pulmonary characteristic impedance, although a feature of mitral stenosis, is not exacerbated by the acute effects of increased distending pressure; 2) pacing tachycardia in mitral stenosis causes little change in the pulmonary impedance spectrum except at low frequencies, where decreased impedance lowers power requirements per unit flow; and 3) relief of mitral stenosis produces immediate improvement in low-frequency impedance and in hydraulic power requirements. These findings suggest that although characteristic impedance may be a measure of the long-term effects of pulmonary hypertension on the pulmonary circulation, acute increases and decreases in PA pressure produce effects on right ventricular load that are best described in terms of the low-frequency properties of the PA system. Improvement in low-frequency impedance diminishes hydraulic power requirements and thus reflects improved ventricular-vascular coupling, irrespective of distending PA pressure. Efforts to treat or prevent right heart failure in the presence of pulmonary hypertension should take account of the potential benefit of changes in low-frequency impedance characteristics of the pulmonary vascular bed.

Emergent use of balloon-expandable coronary artery stenting for failed percutaneous transluminal coronary angioplasty

BACKGROUND

The balloon-expandable intracoronary stent developed by Palmaz and Schatz is undergoing clinical evaluation for use in unfavorable anatomic situations and in the prevention of restenosis. Because the stent's mechanism of action would suggest effectiveness in salvaging certain percutaneous transluminal coronary angioplasty (PTCA) failures, we retrospectively examined the results of emergency unplanned coronary artery stenting for failed PTCA procedures, including acute occlusion.

METHODS AND RESULTS

The study population consisted of all US patients receiving emergency unplanned stent implantation in a nonrandomized fashion at seven centers over a 2 1/2-year period (n = 56). All available medical records and angiograms were reviewed to determine retrospectively the reason for stenting: Group 1 consisted of 23 patients with a suboptimal angioplasty result; group 2 included patients with evidence of impending vessel closure after PTCA (n = 15); and group 3 were patients with frank acute occlusion after PTCA (n = 18). The immediate and final (30-day) results of stenting were examined with respect to major complications, which included death, need for coronary artery bypass graft surgery, and occurrence of myocardial infarction. Finally, restenosis rates (greater than or equal to 50% stenosis) based on follow-up angiography were calculated. Baseline characteristics of the study population included a mean +/- SD age of 58 +/- 11 years and a large prevalence of angiographic characteristics generally considered unfavorable for PTCA, which include lesion eccentricity (49%), intimal dissection (9%), or angiographically visible thrombus (6%). After conventional balloon angioplasty, there was an increased incidence of intimal dissection (74%) and thrombus formation (38%), and overall stenosis severity was unchanged (75 +/- 12% versus 70 +/- 27%, p = NS). Successful stent deployment was achieved in 55 (98%) of 56 patients with initial success (freedom from death, surgery, and infarction) in 52 (93%) of 56 patients. The success rate at 1 month fell to 71% primarily because of the occurrence of subacute stent thrombosis (16%) and its associated complications. Overall, major complications occurred in 16 (29%) of 56 patients within 30 days. The only predictor of subacute stent thrombosis in multiple stepwise logistic regression analysis was the presence of angiographically visible thrombus after stenting (p = 0.03). Angiographic restenosis was documented in eight (23%) of 35 eligible patients.

CONCLUSIONS

Emergency stenting may be a useful and effective treatment for failed angioplasty. High initial success rates (greater than 90%) can be achieved, but subsequent complications, often related to subacute thrombosis, occur in a substantial portion of patients. Patients who receive stents on an emergency basis, particularly those with previous acute occlusion, should be considered to be at greater than usual risk for complications and receive more careful anticoagulation and follow-up.

Coronary angiography and interventional cardiology

Percutaneous transluminal coronary angioplasty has become the most commonly applied coronary revascularization procedure. Its growth is due to expanding indications and new patient populations including patients with multivessel coronary artery disease, acute myocardial infarction or cardiogenic shock, and elderly patients. Success rates and complications for percutaneous transluminal coronary angioplasty have remained the same or improved despite the expanding indications and the persistent problem of restenosis. Several recent studies have examined new biologic approaches to restenosis. However, the most exciting area of interventional cardiology continues to be the use and development of new mechanical devices including stents, lasers, and atherectomy for unfavorable anatomic lesions, acute occlusion after angioplasty, and to prevent restenosis. The gold standard in the assessment of coronary disease is still angiography, but newer imaging techniques including intravascular ultrasound and angioscopy have added to our understanding of angioplasty, unstable angina, and the use of new devices.

Management and immediate outcome of patients with intracoronary thrombus during percutaneous transluminal coronary angioplasty

A retrospective analysis of our experience with intraprocedural thrombus complicating percutaneous transluminal coronary angioplasty (PTCA) was undertaken. Of 983 PTCA procedures reviewed, 62 (6.3%) were complicated by thrombus. Patients were managed conservatively (group I, n = 18), with redilation (group II, n = 17), or with intracoronary urokinase and redilation (group III, n = 27). The three groups did not differ with respect to demographic or baseline angiographic variables, but complications, defined as death, myocardial infarction, bypass surgery, or threatened occlusion requiring emergency stenting, occurred in 11% of patients in group I, 24% in group II, and 48% in group III. Occlusive thrombus behavior was observed in 80% of these 62 patients. Patients with complications were less likely to have received antecedent antiplatelet therapy (79% vs 95% of patients without complications), had more complex baseline lesion morphology, more often had thrombus present at baseline (42% vs 19%), and more often had a low activated clotting time at the start of PTCA (53% vs 8%). Thrombi that led to complications more frequently exhibited occlusive behavior before therapy was begun (95% vs 71%) and more often occurred in the setting of intimal dissection (42% vs 14%). Patients undergoing PTCA at the time of diagnostic catheterization were more likely to have complications than those in whom PTCA was delayed. A successful outcome was more likely (83% vs 27%, p = 0.03) in group III if at least 140,000 U of urokinase were administered within 50 minutes of the appearance of thrombus. Thus intracoronary thrombus formation during PTCA remains a significant source of morbidity.(ABSTRACT TRUNCATED AT 250 WORDS)

Factors influencing immediate results, complications, and short-term follow-up status after Inoue balloon mitral valvotomy: a North American multicenter study

Clinical trials with the Inoue mitral valvotomy balloon have recently begun in the United States. We assessed the effects of 17 demographic, echocardiographic, procedural, and hemodynamic variables on the immediate results, complications, and short-term follow-up of 200 patients in 15 centers undergoing valvotomy with this device. The study population had a mean age +/- SD of 53 +/- 15 years, and the total echocardiographic score was 7.2 +/- 2.4. Valvotomy was technically successful in 96.5% of procedures and increased the mean mitral valve area from 1.0 +/- 0.3 to 1.8 +/- 0.7 cm2 (p less than 0.001); 72% had an increase in valve area greater than or equal to 50%, and 67% had a final area greater than or equal to 1.5 cm2. Major procedural complications included cardiac tamponade during transseptal puncture (1.0%), systemic embolism (1.5%), and severe mitral regurgitation (2.4%); there were no procedural deaths and one hospital death. Multivariate analysis identified the absence of prior surgical commissurotomy and younger age as significant predictors of the gain in mitral valve area, but the correlation coefficients were low. Although the absence of subvalvular disease on echocardiograms was a predictor of a final valve area greater than or equal to 1.5 cm2, the total echocardiographic score did not correlate well with the immediate outcome (r = 0.01, p = NS). No variable was identified as predictive of restenosis, which occurred according to echocardiographic criteria in 14 of 66 (21%) patients evaluated 6 months after valvotomy. Good hemodynamic results with valvotomy were achieved in the majority of patients with low complication rates by many investigators with the use of the Inoue balloon device.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of atrial natriuretic peptide on myocardial contractile and diastolic function in patients with heart failure

Atrial natriuretic peptide alters left ventricular performance in patients with heart failure. To assess the direct effects of this hormone on myocardial function, its actions were compared with those of the pure vasodilator nitroprusside in 10 patients with heart failure. Simultaneous left ventricular micromanometer pressure and radionuclide volume were obtained during a baseline period, during nitroprusside infusion, during a second baseline period and during atrial natriuretic peptide infusion. The baseline end-systolic pressure-volume relation was generated in nine patients from pressure-volume loops obtained during the two baseline periods and during afterload reduction with nitroprusside. Mean arterial pressure decreased with atrial natriuretic peptide (89 +/- 3 to 80 +/- 2 mm Hg, p less than 0.05) and by a greater amount with nitroprusside (90 +/- 4 to 73 +/- 3 mm Hg, p less than 0.05). Left ventricular end-diastolic pressure also decreased with atrial natriuretic peptide (24 +/- 2 to 16 +/- 3 mm Hg, p less than 0.05) and by a greater amount with nitroprusside (24 +/- 2 to 13 +/- 3 mm Hg, p less than 0.05). Cardiac index increased during infusion of each agent from 2.0 +/- 0.2 to 2.4 +/- 0.2 liters/min per m2 (p less than 0.01). Heart rate increased slightly with nitroprusside but did not change with atrial natriuretic peptide. Peak positive first derivative of left ventricular pressure (dP/dt), ejection fraction and stroke work index were unchanged by either agent. The relation between end-systolic pressure and volume during atrial natriuretic peptide infusion was shifted slightly leftward from the baseline value in four patients, slightly rightward in four and not at all in one patient, indicating no consistent inotropic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of valve deformity on results and mitral regurgitation after Inoue balloon commissurotomy

BACKGROUND

The effect of valve deformity and patient age adversely affect the results of percutaneous transvenous mitral commissurotomy (PTMC) with conventional balloons.

METHODS AND RESULTS

These factors were characterized after PTMC with the Inoue balloon. The increases in mitral valve area and mitral regurgitation after the procedure were evaluated comparing echocardiographic score of 8 or less versus more than 8, age of less than 60 versus age of 60 years or more, and age of less than 70 versus age of 70 years or more. One hundred sixty-two patients (mean age, 52 +/- 14 years) were studied. For the entire group, mitral valve area increased from 1.0 to 1.8 cm2 (p less than 0.001). Valve area increased from 1.0 +/- 0.3 to 1.8 +/- 0.6 cm2 in patients with echocardiographic score of 8 or less (n = 102) and from 1.0 +/- 0.3 to 1.7 +/- 0.5 cm2 with echocardiographic score of more than 8 (n = 44). Patients less than 60 years old (n = 104) had increases in valve area from 1.0 +/- 0.3 to 1.8 +/- 0.6 cm2 versus 1.0 +/- 0.4 to 1.8 +/- 0.6 cm2 for those 60 years old or older (n = 50) (p = NS). There was no significant difference in resultant valve area when the age division was increased to less than 70 versus 70 years or more. Similarly, the percentage of patients with 2+ or greater increase in mitral regurgitation was not different for those with higher than for those with lower echocardiographic scores (4% versus 12%, p = NS), age of less than 60 versus age of 60 years or more (10% versus 10%, p = NS), or age of less than 70 versus age of 70 or more years (9% versus 18%, p = NS). Valve replacement for mitral regurgitation was performed in four patients (one emergency), all with echocardiographic scores of less than 8.

CONCLUSIONS

Age and extent of valve deformity do not have significant effects on acute results of PTMC using the Inoue balloon. Unique balloon geometry or the controlled, stepwise balloon sizing may explain these acceptable acute results in patients with more-deformed valves.

Adaptation to ischemia during percutaneous transluminal coronary angioplasty. Clinical, hemodynamic, and metabolic features

The clinical, electrocardiographic, and coronary hemodynamic responses to sequential 90-second occlusions of the left anterior descending coronary artery in 12 patients undergoing elective percutaneous transluminal coronary angioplasty were examined. Transmyocardial lactate metabolism was examined in an additional group of seven patients with clinical and hemodynamic features similar to the first group. We noted that in comparison with the initial balloon occlusion the second occlusion was characterized by less subjective anginal discomfort, less ST segment shift (0.44 +/- 0.13 versus 0.21 +/- 0.07 mV, p = 0.01), and lower mean pulmonary artery pressure (25 +/- 1.0 versus 20 +/- 1.7 mm Hg, p = 0.005). In addition, for the same heart rate-blood pressure product, cardiac vein flow during the second inflation was significantly lower than that recorded during the first inflation (96 +/- 1.4 versus 83 +/- 2.4 ml/min, p = 0.005). Finally, there was significantly less myocardial lactate production during the second inflation (lactate extraction ratio: first inflation, -0.11 +/- 0.03; second inflation, -0.03 +/- 0.02; p = 0.04). We conclude that the lessened clinical, electrocardiographic, hemodynamic, and metabolic evidence of myocardial ischemia during the second of two periods of coronary artery occlusion during percutaneous transluminal coronary angioplasty supports the concept of adaptation to myocardial ischemia (ischemic preconditioning).

Coronary hemodynamic effects of atrial natriuretic peptide in humans

Studies of the effects of atrial natriuretic peptide on the coronary circulation have yielded conflicting results in animals and have not been fully investigated in human subjects. To further characterize the direct coronary hemodynamic actions of atrial natriuretic peptide in humans and to assess the safety of its administration in patients with coronary artery disease, incremental doses of synthetic atrial natriuretic peptide and nitroglycerin were infused into the left coronary artery in 14 patients, 11 of whom had coronary artery disease. Both agents caused dose-related increases in total coronary sinus blood flow. The largest dose of atrial natriuretic peptide given to all patients (100 micrograms) increased mean coronary sinus blood flow from 127 +/- 7 to 149 +/- 9 ml/min (p less than 0.05) and decreased coronary vascular resistance from 0.93 +/- 0.07 to 0.81 +/- 0.05 mm Hg/ml per min (p less than 0.05); mean arterial blood pressure and heart rate were not affected by this dose of atrial natriuretic peptide. The greatest changes in coronary sinus blood flow (+25%) and coronary vascular resistance (-18%) after atrial natriuretic peptide administration occurred in the patients with coronary artery disease and no other associated cardiovascular disease. The maximal effects of atrial natriuretic peptide were similar to those of nitroglycerin, and no untoward effects were observed. Thus, atrial natriuretic peptide is a direct coronary vasodilator in humans. Its maximal dose effects are similar to those of nitroglycerin and were well tolerated in this small group of patients. The physiologic importance and therapeutic potential of atrial natriuretic peptide in patients with coronary artery disease merit further investigation.

Multicenter trial of oral enoximone in patients with moderate to moderately severe congestive heart failure. Lack of benefit compared with placebo. Enoximone Multicenter Trial Group

A multicenter double-blind, randomized, placebo-controlled trial of oral enoximone, a phosphodiesterase inhibitor, was conducted in 102 outpatients (50 receiving enoximone and 52 receiving placebo) with moderate to moderately severe congestive heart failure. All were on a long-term regimen of digoxin and diuretics without vasodilators and converting enzyme inhibitors. Symptom score was obtained, and exercise testing was performed monthly for 4 months. There were no differences between groups in symptoms or exercise duration at the end of 4 months. A subgroup undergoing analysis of oxygen consumption with measurement of anaerobic threshold during exercise showed an increase (p less than 0.05) in anaerobic threshold at 1 month with enoximone. (2.7 +/- 0.8 ml O2/kg/min) compared with placebo (-0.8 +/- 1.2 ml O2/kg/min). This improvement was not sustained at 4 months (0.5 +/- 1.7 ml O2/kg/min with enoximone and 0.2 +/- 1.5 ml O2/kg/min with placebo). The dropout rate was significantly higher (p less than 0.02) with enoximone (46%) than with placebo (25%). Adverse effects other than death were slightly, but not significantly, higher with enoximone (32%) than with placebo (22%). During therapy, five deaths occurred in the enoximone group, and none occurred in the placebo group (p less than 0.05). Two deaths were sudden, two were from progressive congestive heart failure, and one was from acute myocardial infarction. With intention-to-treat analysis and inclusion of patients who were removed from therapy because of lack of study drug effect, 10 deaths occurred in the enoximone group, and three occurred in the placebo group (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular effects of intracoronary atrial natriuretic peptide administration in man

An intracoronary drug infusion protocol was employed to assess the hemodynamic effects of synthetic atrial natriuretic peptide in normal subjects and to evaluate its actions on epicardial coronary artery dimensions. Increasing concentrations of synthetic atrial natriuretic peptide (1.75 to 84 micrograms/min) were infused at a constant rate directly into the left coronary artery in eight patients with normal left ventricular function and left coronary artery angiograms. Steady-state hemodynamic parameters and high-fidelity left ventricular pressure were recorded at each dose and indexes of left ventricular contractile and diastolic function were calculated. Coronary angiograms obtained at baseline and the highest dose of atrial natriuretic peptide were compared by quantitative image analysis techniques. At the highest dose administered, atrial natriuretic peptide decreased mean pulmonary artery pressure (-36%, p less than 0.01), pulmonary capillary wedge pressure (-80%, p less than 0.01), left ventricular end-diastolic pressure (-58%, p less than 0.01), left ventricular end-systolic pressure (-11%, p less than 0.01), mean arterial pressure (-8%, p less than 0.05), and pulmonary vascular resistance (-18%, p less than 0.05). Cardiac output and systemic vascular resistance were unchanged, and heart rate and peak positive dP/dt increased. Peak negative dP/dt and the time constant of early diastolic relaxation calculated by the logarithmic method both fell at the highest dose of atrial natriuretic peptide, although the time constants calculated by other less load-sensitive methods were unchanged. Doses of intracoronary atrial peptide that did not alter left ventricular load had no effect on indexes of left ventricular systolic or diastolic function despite a presumably high intramyocardial concentration of the agent.(ABSTRACT TRUNCATED AT 250 WORDS)

The M-Heart percutaneous balloon mitral Valvuloplasty Registry: initial results and early follow-up. The M-Heart Group

The initial results, complications and early follow-up of 74 patients undergoing percutaneous balloon mitral valvuloplasty in seven hospitals participating in a multicenter registry are reported. Seventy-four patients with a mean age of 53 years had 75 valvuloplasty procedures performed over a 2.5 year period. Eighty-nine percent of the attempted procedures were completed and resulted in an increase in mean mitral valve area from 1.0 +/- 0.04 to 2.0 +/- 0.1 cm2 (p less than 0.0001); the valve area increased greater than or equal to 50% of the baseline valve area in 73% of the patients. Major complications included procedure-related death (2.7%), cardiac tamponade (6.7%), systemic embolism (2.7%) and emergency surgery (6.7%). At a mean follow-up period of 14.6 months, the condition of the majority of patients had improved, and 89% of 55 patients treated only with valvuloplasty were in New York Heart Association functional class I or II. Thus, hemodynamic and clinical improvement can be obtained in the majority of patients with mitral stenosis treated with balloon valvuloplasty in multiple centers. However, suboptimal results and major complications occurred in a significant number of patients and may limit this procedure to use by experienced operators in hospitals with facilities for cardiac surgery.

Techniques for assessing inotropic effects of drugs in patients with heart failure: application to the evaluation of nicardipine

Evaluation of new drugs for the treatment of patients with heart failure requires assessment of the inotropic effects of these agents. Use of traditional indexes of contractility has been limited by the confounding effects of load on these measures of contractile function, although they have yielded meaningful conclusions in some studies. Recently, the end-systolic pressure volume relation (ESPVR) has emerged as a relatively load-independent measure of contractility. Because it is difficult to construct the relation in the clinical setting, several approximations have been introduced, some of which have significant limitations. We have applied the ESPVR to the assessment of the inotropic effect of the new dihydropyridine calcium channel blocker, nicardipine, in 15 patients with heart failure caused by systolic dysfunction. We constructed left ventricular pressure-volume loops from micromanometer pressure and radionuclide volume and manipulated afterload with nitroprusside. In response to intravenous nicardipine, mean arterial pressure fell from 91 +/- 4 (mean +/- SEM) to 72 +/- 2 mm Hg, left ventricular end-diastolic pressure fell from 27 +/- 2 to 23 +/- 3 mm Hg, cardiac index increased from 1.7 +/- 0.1 to 2.4 +/- 0.1 L/min/m2, and left ventricular ejection fraction increased from 0.15 +/- 0.01 to 0.19 +/- 0.01 (all p less than 0.05). Heart rate did not change. A rightward shift of the ESPVR, indicating a negative inotropic effect of nicardipine, was observed in 12 of 14 patients (p less than 0.05). We conclude that nicardipine improves left ventricular pump performance despite its negative inotropic effect in patients with severe heart failure. The improvement in pump performance can be attributed to afterload reduction.

Hemodynamic and renal effects of atrial natriuretic peptide in congestive heart failure

The hemodynamic and renal effects of anaritide (human atrial natriuretic peptide 102-126), a synthetic analog of atrial natriuretic peptide, were evaluated in 35 patients with chronic New York Heart Association class II to IV heart failure. There were 32 men and 3 women, aged 33 to 75 (mean +/- standard error of the mean 56 +/- 2) years. In the first phase of the study, right-sided heart catheterization was performed, and anaritide was administered as 1-hour infusions. The rate of the infusion varied among patients from 0.03 to 0.3 micrograms/kg/min. In response to anaritide, there were decreases in mean systemic arterial (94 +/- 2 to 87 +/- 2 mm Hg), right atrial (10 +/- 1 to 8 +/- 1 mm Hg), mean pulmonary arterial (33 +/- 2 to 28 +/- 2 mm Hg) and pulmonary artery wedge (22 +/- 2 to 15 +/- 2 mm Hg) pressures (all p less than 0.05). Cardiac index increased (2.39 +/- 0.15 to 2.62 +/- 0.15 liters/min/m2, p less than 0.05) and heart rate was unchanged. Systemic vascular resistance decreased significantly, but pulmonary vascular resistance was unchanged. There were increases in urine volume (1.6 +/- 0.2 to 2.3 +/- 0.4 ml/min), sodium excretion (47 +/- 13 to 74 +/- 20 muEq/min) and fractional excretion of sodium (0.41 +/- 0.11 to 0.59 +/- 0.14%, all p less than 0.05), while potassium excretion and creatinine clearance did not change. In the second phase of the study, patients received 2-hour infusions of anaritide (0.03 to 0.6 micrograms/kg/min) and placebo with noninvasive monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Linearity of the left ventricular end-systolic pressure-volume relation in patients with severe heart failure

The left ventricular end-systolic pressure-volume relation is a relatively load-independent measure of left ventricular contractile function. Linearity of the relation derived from full left ventricular pressure-volume loops has not previously been demonstrated for patients with severe heart failure. Therefore, nine patients with markedly depressed left ventricular systolic function (ejection fraction 0.14 +/- 0.08) were studied with micromanometer left ventricular pressure measurement and simultaneous radionuclide ventriculography. Afterload was reduced with graded infusions of nitroprusside, allowing construction of pressure-volume loops under four afterload conditions in four patients and three afterload conditions in the other five patients. The end-systolic pressure-volume relation derived from the pressure-volume loops was found to be linear for the range of pressures and volumes examined, with correlation coefficients in individual patients ranging from 0.936 to 0.999 (mean 0.981). The mean slope of the relation (or end-systolic elastance) was 0.71 mm Hg/ml (range 0.42 to 1.52), and the extrapolated volume intercept at zero pressure was positive in all patients. An exponential relation between end-systolic elastance and ejection fraction was demonstrated for this group of patients. Approximations of end-systolic elastance obtained from measurements other than the full pressure-volume loops correlated variably with "true" elastance obtained from the pressure-volume loops. The relation between stroke work and end-diastolic volume was nonlinear in most patients. Thus, the end-systolic pressure-volume relation is linear in the "physiologic" range in patients with severe heart failure. This finding should permit construction of the relation from two loading conditions in clinical studies, facilitating its use as an index of contractile function in patients with heart failure.

Percutaneous aortic balloon valvuloplasty in octogenarians: morbidity and mortality

STUDY OBJECTIVE

To examine the morbidity, mortality, and hospital course of an elderly patient sample (mean age, 86 years; 95% CI, 84 to 87) having percutaneous aortic balloon valvuloplasty.

DESIGN

Retrospective consecutive case series before and after balloon valvuloplasty.

SETTING

Tertiary care referral hospital.

PATIENTS

Consecutive sample of 26 patients aged 80 years or older with symptomatic aortic stenosis referred for balloon valvuloplasty from July 1987 to July 1988.

MEASUREMENTS AND MAIN RESULTS

Percutaneous aortic balloon valvuloplasty reduced the transvalvular gradient from 59 (95% CI, 51 to 67) to 31 mm Hg (95% CI, 26 to 35; P less than 0.0001) and increased aortic valve area from 0.45 (95% CI, 0.38 to 0.51) to 0.67 cm2 (95% CI, 0.58 to 0.76; P less than 0.0001). The mean length of hospital stay for the entire study population was 11.2 days (95% CI, 7.3 to 15.2) at a total hospital charge per patient of $29,600 (95% CI, 21,050 to 38,150). For patients having procedural complications (11 complications in 8 patients), surgical procedures, or cardiogenic shock, the mean hospital stay increased to 16.2 days (95% CI, 6.2 to 26.2; P less than 0.05) and the hospital charge increased to $44,400 (95% CI, 24,280 to 64,520; P less than 0.01). Two patients who presented with cardiogenic shock died, and 1 patient had an aortic valve replacement before discharge. Four patients were recently discharged (less than 1 month) and follow-up was obtained in the remaining 19 patients at 6.1 months (95% CI, 4.1 to 8.1). Five more patients, including the remaining patient who presented with cardiogenic shock, died after discharge for an overall mortality of 32%. Twelve of the remaining fourteen patients had fewer symptoms and improved an average of 1.1 New York Heart Association classes (95% CI, 0.7 to 1.4; P less than 0.0001).

CONCLUSIONS

Percutaneous aortic balloon valvuloplasty in patients 80 years and older improves hemodynamics and symptoms of heart failure during short-term follow-up in most patients, but overall mortality is high in this elderly patient population. Hospital charges and length of stay were much higher in patients with complications or coexisting medical illnesses. Valvuloplasty is a reasonable alternative treatment for patients with aortic stenosis who require palliative treatment of symptoms and have high surgical risk.