Atrial septostomy in the treatment of severe pulmonary arterial hypertension

BACKGROUND

Atrial septostomy (AS) may improve symptoms and haemodynamics in patients with severe pulmonary arterial hypertension (PAH).

METHODS

Twenty AS performed in 17 patients with severe progressive PAH (13 primary pulmonary hypertension, two collagen vascular disease, one thromboembolic disease, one vaso-occlusive disease) were analysed. Seven patients were in NYHA class III and 10 in NYHA IV. Fifteen patients were on long term prostanoid treatment. AS was performed under fluoroscopy using graded balloon technique.

RESULTS

AS improved clinical symptoms and increased the cardiac index from 1.8 to 2.2 l/min/m(2) and systemic oxygen transport from 263.2 to 329.6 ml/min/m(2) (p<0.001). Procedure related complications included one non-fatal atrial puncture and one unsuccessful septal puncture. Four patients died within 1 week of surgery from uncontrolled tachyarrhythmia (n=1), severe hypoxaemia (n=1), and multiorgan failure (n=2). One further patient died after voluntarily discontinuing renal dialysis. Twelve patients are alive 5-17 months after the operation with five patients undergoing heart-lung transplantation. There were no differences in haemodynamic and functional parameters between the non-survivors and the mid term survivors. However, the non-survivors were significantly older (52 v 36 years, p<0.01) and had a significantly lower creatinine clearance rate (70 ml/min v 48 ml/min, p<0.05).

CONCLUSION

Atrial septostomy improves clinical symptoms, cardiac index, and systemic oxygen transport and has the potential to influence the prognosis in selected cases of severe PAH.

Ostial left anterior descending coronary artery stent positioning: partial preinflation prevents stent oscillation and facilitates accurate deployment

Ostial intracoronary stent deployment is complicated by the influence of cardiac motion, which causes the stent to oscillate back and forth during the cardiac cycle. Accurate deployment can be facilitated by initial low pressure inflation of the balloon on which the stent is mounted. This stabilizes the stent within the stenosis, while still allowing adjustment of the exact stent location prior to deployment.

Coronary flow reserve improves after aortic valve replacement for aortic stenosis: an adenosine transthoracic echocardiography study

OBJECTIVES

The goal of this study was to assess coronary flow reserve (CFR) before and after aortic valve replacement (AVR).

BACKGROUND

Coronary flow reserve is impaired under conditions of left ventricular (LV) hypertrophy. It is not known whether CFR improves with regression of LV hypertrophy in humans.

METHODS

We investigated 35 patients with pure aortic stenosis, LV hypertrophy and normal coronary arteriograms. Patients underwent adenosine transthoracic echocardiography on two occasions--immediately before AVR and six months postoperatively. Left ventricular mass, distal left anterior descending coronary artery (LAD) diameter, flow and CFR were assessed on each occasion.

RESULTS

Distal LAD diameter was successfully imaged in 30 patients (86%), and blood flow was successfully imaged in 27 (77%). Paired data were subsequently available in 24 patients, of whom 14 were men, mean age 68.1+/-12.5 years, body mass index 24.5+/-2.0 kg/m2, aortic valve gradient 93+/-32 mm Hg. Pre- to post-AVR a significant decrease was seen in LV mass (271+/-38 vs. 236+/-32g, p<0.01) and LV mass index (154+/-21 vs. 134+/-21 g/m2, p< 0.01). Distal LAD diameter fell from 2.27+/-0.37 to 2.23+/-0.35 mm, p = 0.08). Pre- to post-AVR there was no significant change in resting parameters of peak diastolic velocity (0.43+/-0.16 vs. 0.41+/-0.11 m/s), distal LAD flow 23.3+/-10.1 vs. 20.9+/-5.2 ml/min or distal LAD flow scaled for LV mass (8.7+/-3.8 vs. 9.0+/-2.5 ml/min/100 g LV mass), but there was significant increase in hyperemic peak diastolic velocity (0.71+/-0.26 vs. 1.08+/-0.24 m/s; p<0.01), distal LAD flow (37.8+/-11.3 vs. 53.5+/-16.1 ml/min; p<0.01) and distal LAD flow scaled for LV mass (14.3+/-5.0 vs. 23.3+/-8.5 ml/min/100 g LV mass; p<0.01). Coronary flow reserve, therefore, increased from 1.76+/-0.5 to 2.61+/-0.7.

CONCLUSIONS

Coronary flow reserve increases after AVR for aortic stenosis. This increase occurs in tandem with regression of LV hypertrophy.

Coronary flow reserve is supranormal in endurance athletes: an adenosine transthoracic echocardiographic study

OBJECTIVE

To compare coronary flow reserve in endurance athletes and healthy sedentary controls, using adenosine transthoracic echocardiography.

METHODS

29 male endurance athletes (mean (SD) age 27.3 (6.6) years, body mass index (BMI) 22.1 (1.9) kg/m(2)) and 23 male controls (age 27.2 (6.1) years, BMI 23.9 (2.6) kg/m(2)) with no coronary risk factors underwent transthoracic echocardiographic assessment of distal left anterior descending coronary artery (LAD) diameter and flow, both at rest and during intravenous adenosine infusion (140 microg/kg/min).

RESULTS

Distal LAD diameter and flow were adequately assessed in 19 controls (83%) and 26 athletes (90%). Distal LAD diameter in athletes (2.04 (0.25) mm) was not significantly greater than in sedentary controls (1.97 (0.27) mm). Per cent increase in LAD diameter following 400 microg sublingual nitrate was greater in the athletes than in the controls, at 14.1 (7. 2)% v 8.8 (5.7)% (p < 0.01). Left ventricular mass index in athletes exceeded that of controls, at 130 (19) v 98 (14) g/m(2) (p < 0.01). Resting flow among the athletes (10.6 (3.1) ml/min; 4.4 (1.2) ml/min/100 g left ventricular mass) was less than in the controls (14.3 (3.6) ml/min; 8.2 (2.2) ml/min/100 g left ventricular mass) (both p < 0.01). Hyperaemic flow among the athletes (61.9 (17.8) ml/min) exceeded that of the controls (51.1 (14.6) ml/min; p = 0.02), but not when corrected for left ventricular mass (25.9 (5.6) v 28.5 (7.4) ml/min/100 g left ventricular mass; NS). Coronary flow reserve was therefore substantially greater in the athletes than in the controls, at 5.9 (1.0) v 3.7 (0.7) (p < 0.01).

CONCLUSIONS

Coronary flow reserve in endurance athletes is supranormal and endothelium independent vasodilatation is enhanced. Myocardial hypertrophy per se does not necessarily impair coronary flow reserve. Adenosine transthoracic echocardiography is a promising technique for the investigation of coronary flow reserve.

Inoue balloon mitral valvuloplasty: long-term clinical and echocardiographic follow-up of a predominantly unfavourable population

AIMS

To assess long-term outcome in a typical Western population of predominantly unfavourable patients undergoing Inoue balloon mitral valvuloplasty. Outcome amongst patients has only been undertaken in the medium term. Long-term echocardiographic data in particular are scarce.

METHODS

Inoue mitral valvuloplasty was attempted in 106 patients. There were six technical failures; the procedure was therefore completed in 100 patients, who underwent annual clinical and echocardiographic follow-up.

RESULTS

Patients were aged 63.5+/-10. 3 years. 82% were female. Unfavourable characteristics included age >65 (52%), NYHA class III or IV (87%), >/=1 significant co-morbidity (63%), atrial fibrillation (82%), previous surgical commissurotomy (25%) and echocardiographic score >8 (59%, mean 8.9+/-2.1). Mitral valve area increased from 0.98+/-0.23 to 1.54+/-0.31 cm(2). There were three major complications. Post-procedure, symptoms improved in 88% of patients. Haemodynamic success (mitral valve area increase >50%, final mitral valve area >1.5 cm(2), mitral regurgitation </=grade 2) was achieved in 61% of cases. Mean follow-up was 4.3+/-1. 4 years. Survival was 97%, 88% and 82% at 1, 3 and 6 years. Event-free survival (freedom from death, mitral valve replacement or repeat valvuloplasty) was 96%, 82% and 56% at 1, 3 and 6 years. Freedom from restenosis (loss of >50% gain in mitral valve area, mitral valve area <1.5cm (2)) was 98%, 92% and 75% at 1, 3 and 6 years. Pre-procedural predictors of event-free survival were male sex, absence of co-morbidities, lower echocardiographic score and smaller left atrial diameter.

CONCLUSIONS

In a Western population with predominantly unfavourable characteristics for mitral valvuloplasty, long-term outcome post-procedure is reasonable. A moderate increase in mitral valve area can be achieved at low procedural risk, and the subsequent rate of restenosis is low. Nonetheless, 6 years after the procedure, half of the patients will have required further intervention or died. For fitter patients willing to accept significant operative risk, mitral valve replacement remains a valuable alternative.

Noninvasive indexes of left atrial diastolic function in hypertrophic cardiomyopathy

OBJECTIVES

Our goal was to noninvasively assess left atrial diastolic function and its relation to the impaired left ventricular filling in patients with hypertrophic cardiomyopathy.

METHODS AND RESULTS

We studied 34 patients with hypertrophic cardiomyopathy, 26 patients with secondary forms of left ventricular hypertrophy (aortic stenosis, fixed subaortic stenosis, hypertension), and 21 control subjects. Left atrial diastolic function was assessed by measuring acceleration time (SAT), deceleration time (SDT), and the EF (mean deceleration rate) slope of the pulmonary venous flow systolic wave (SW). Left ventricular diastolic function assessed by transmitral Doppler included peak early left ventricular and peak atrial filling velocities, the ratio of early-to-late peak velocities, isovolumic relaxation time, deceleration time, and EF slope. In patients with hypertrophic cardiomyopathy, acceleration time was significantly reduced (P<.05), deceleration time was significantly prolonged (P<.0001), and EF slope was significantly reduced (P<.01). These indexes were similar among the other two groups. No statistically significant difference existed between the subgroups of hypertrophic cardiomyopathy in the above indexes. Patients with hypertrophic cardiomyopathy and secondary forms of left ventricular hypertrophy had evidence of left ventricular diastolic dysfunction. In patients with hypertrophic cardiomyopathy, no correlation existed between left atrial and left ventricular diastolic function indexes (r = -0.26 to 0.33).

CONCLUSIONS

Echocardiographic indexes of left atrial relaxation and filling are abnormal in patients with hypertrophic cardiomyopathy but not in secondary forms of left ventricular hypertrophy. These indexes are abnormal in all forms of hypertrophic cardiomyopathy irrespective of left ventricular outflow tract obstruction and distribution of hypertrophy; they are not solely attributable to left ventricular diastolic dysfunction. The above may imply that hypertrophic cardiomyopathy is a cardiac myopathic disease that involves the heart muscle as a whole, irrespective of distribution of hypertrophy and obstruction.

Comparison of central venous and inferior vena caval pressures

Inferior vena caval pressures were measured in 60 patients undergoing cardiac catheterization and compared with central venous pressure from within the right atrium. Mean pressures within the abdominal inferior vena cava were essentially the same as mean right atrial pressure, suggesting that the inferior vena cava provides a useful safe alternative for measuring central venous pressure.

Pulmonary capillary wedge pressure in mitral stenosis accurately reflects mean left atrial pressure but overestimates transmitral gradient

Current opinion varies as to whether pulmonary capillary wedge pressure assessment of transmitral gradient in mitral stenosis is accurate; we therefore compared transmitral gradient in 36 patients awaiting balloon valvuloplasty using both pulmonary capillary wedge pressure and direct left atrial pressure. Mean pulmonary capillary wedge pressure correlated well with mean left atrial pressure (limits of agreement -1.5 to +3.7 mm Hg), but mean diastolic mitral gradient calculated using pulmonary capillary wedge pressure differed significantly from that calculated using left atrial pressure (limits of agreement -1.2 to +9.8 mm Hg): wedge pressure-assessed transmitral gradient is therefore misleading, routinely overestimating stenosis severity.

Coronary angiography in the presence of peripheral vascular disease: femoral or brachial/radial approach?

Peripheral vascular disease is considered a relative contraindication to the femoral approach for coronary angiography, but no data exist comparing the femoral and brachial/radial routes under these circumstances. We examined the influence of vascular approach on outcome. Two hundred and ninety-seven patients, mean age 67.1 +/- 8.4 years, with clinical or radiographic evidence of aortofemoral peripheral arterial disease underwent diagnostic coronary angiography during a 3-year period at this cardiothoracic center. The approach was successful in 121 of 154 femoral cases (79%) compared with 130 of 143 brachial/radial cases (91%; P < 0.01). Of the 33 failed femoral cases, 15 were then approached from the other femoral artery, with success in 6 (40%), while 18 were approached from the arm, with success in all (100%; P < 0.01). Brachial/radial cases took significantly longer than femoral cases (51 +/- 19 vs. 42 +/- 22 mins; P < 0.01). In cases where the femoral pulse was considered normal, the femoral approach nonetheless failed in 19 of 95 (20%). Major vascular complications (e.g., pulseless limb, arterial dissection, hemorrhage, or false aneurysm) occurred in nine femoral cases vs. zero brachial/radial cases (P < 0.01). Patients with peripheral vascular disease who undergo coronary angiography from the femoral artery have a 1-in-5 risk of procedural failure, necessitating use of an alternative vascular approach, and a 1-in-20 risk of a major vascular complication. Normality of femoral arterial pulsation is not a good predictor of femoral success. Brachial/radial approaches take longer, but succeed more frequently and have a negligible major vascular complication rate. We believe that patients with peripheral vascular disease should undergo coronary angiography via brachial or radial approach. Cathet. Cardiovasc. Intervent. 49:32-37, 2000.