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2. Smith B, Barnea O, Moore TW, Jaron D. Optimal control system forthe intra-aortic balloon pump. Med Biol Eng Comput 1991;29:180 –184.3. Kantrowitz A, Cardona RR, Freed PS. Percutaneous intra-aortic ballooncounterpulsation. Crit Care Clin 1992;8:819–837.4. Kern MJ, Aguirre FV, Tatineni S, Penick D, Serota H, Donohue T, WalterK. Enhanced coronary blood flow velocity during intraaortic balloon coun-

terpulsation in critically ill patients. J Am Coll Cardiol 1993;21:359 –368.5. Webster H, Veasy LG. Intra-aortic balloon pumping in children. Heart Lung1985;14:548–555.6. Park JK, Hsu DT, Gersony WM. Intraaortic balloon pump managementof refractory congestive heart failure in children. Pediatr Cardiol 1993;14:19–22.

Usefulness of Atrial Septostomy as a Treatmentfor Primary Pulmonary Hypertension and

Guidelines for its Application

Stuart Rich, MD, Emad Dodin, MD, and Vallerie V. McLaughlin, MD

The notion that right-to-left shunting might bebeneficial in primary pulmonary hypertension

(PPH) was first suggested by Rozkovec et al1 in astudy of patients with PPH in whom the presenceof a patent foramen ovale was associated with im-proved survival. A similar observation was madeby Glanville et al,2 who studied the survival of pa-tients referred for lung transplantation due to PPHwho were not transplanted. Atrial septostomy, thecreation of an intraatrial right-to-left shunt, hasbeen reported to be a palliative treatment of pa-tients with advanced pulmonary hypertension.3 – 6

However, since the first reported case on this in-tervention in 1983, there have been little data de-scribing the acute hemodynamic changes, short-and long-term benefits, and procedure-relatedmortality. We have intermittently offered atrialseptostomy to patients with advanced pulmonaryhypertension that is refractory to medical therapysince 1983. We now compare our institutional ex-perience with the 2 largest published series4,5 toanalyze the acute hemodynamic effectiveness ofatrial septostomy, better understand the factors as-sociated with procedure-related mortality, and de-velop guidelines for its clinical application.

j j j

Between July 1983 and June 1995, we per-formed blade balloon atrial septostomy in 6 pa-tients (5 women and 1 man, ages 22 to 55 years)with severe PPH. All were markedly symptomaticand had failed conventional therapy, which in-cluded digoxin, diuretics, anticoagulants, and oralvasodilators. In 2 patients the procedure was per-formed in a semi-emergency setting because thepatients were in refractory right ventricular failureand unresponsive to all other therapeutic treat-

From the Sections of Cardiology, Rush-Presbyterian–St. Luke’s Medi-cal Center, and the University of Illinois at Chicago, Chicago, Illinois.Dr. Rich’s address is: Rush Heart Institute, Center for Pulmonary HeartDisease, Rush-Presbyterian–St. Luke’s Medical Center, 1725 WestHarrison Street, Chicago, Illinois 60612-3824. Manuscript receivedDecember 16, 1996; revised manuscript received and acceptedApril 1, 1997.

ments. In the remaining 4 patients the procedurewas performed electively.

All patients gave informed consent to the proce-dure, which was approved by the institutional reviewboard. In addition, arterial oxygen saturation at restusing pulse oximetry had to be ¢90% on room air.Left-sided heart catheterization was performed usinga 7Fr pigtail catheter. Right-sided cardiac catheter-ization was performed using a balloon flow-directedcatheter. A second right femoral venous puncturewas made for an 8Fr Mullins sheath and dilator. Atransseptal puncture was made through the Mullinssheath and dilator using a Brockenbrough needle. A20-mm Park blade catheter was utilized for the bladeseptostomy. We defined a successful procedure as areduction in systemic arterial oxygen saturation be-tween 5% and 10% from baseline. In 2 patients inwhom blade passage alone was inadequate, a Mans-field balloon, ranging from 4 to 15 mm, was passedthrough the created atrial septostomy and dilationswere made until adequate arterial oxygen saturationchanges were achieved.

Hemodynamics, systemic and pulmonary arterialoxygen saturation, and oxygen consumption mea-surements were made before and after the procedurein all patients. The procedures were performed onroom air. Oxygen transport was calculated from theoxygen content and the cardiac index.5

Significance was defined as a 2-tailed p valueõ0.05. Descriptive variables are presented as mean{ SD. Comparisons between baseline and postpro-cedure data were made using the Student’s t test forpaired data.

Six patients underwent atrial septostomy be-cause of severe PPH characterized by an elevatedpulmonary artery mean pressure (67 { 25 mm Hg),elevated right atrial pressure (17 { 8 mm Hg), andreduced cardiac index (1.7 { 0.65 L/min/m2) (Ta-ble I). Three patients are currently alive and sub-jectively improved. All 3 have exercise-inducedhypoxemia and slightly (but not significantly) im-proved exercise tolerance, with no occurrence ofright ventricular failure since the procedure (mean

370 THE AMERICAN JOURNAL OF CARDIOLOGYT VOL. 80 AUGUST 1, 1997

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TABLE I Acute Hemodynamic Effects of Atrial Septostomy

PatientAge (yr)& Sex FC

Baseline

PAP RAP LAP SAP CI AO% PA% PVR SOT

1 39 F 3 43 4 6 82 2.9 93 71 8.9 5032 44 F 4 57 9 6 97 1.14 89 45 27.5 2123 41 F 4 55 21 5 73 1.91 83 46 17.2 2524 45 F 3 62 16 2 91 2.03 94 54 19.2 3245 42 M 4 64 32 27 53 1.23 95 62 15.5 2536 22 F 4 120 22 5 80 1.04 87 17 55 217

Mean 38.8 66.8 17.3 8.5 79.3 1.7 90.2 49.2 23.9 302SD 7.77 24.7 8.4 8.4 14.1 0.65 4.3 16.9 18.9 101

TABLE I (Continued)

Patient

Postprocedure

PAP RAP LAP SAP CI AO% PA% PVR SOT

1 49 4 4 83 3.78 95 75 8.75 6692 61 6 5 95 1.46 80 44 22.7 2453 53 19 6 72 2.19 85 52 10.6 2964 62 6 7 95 2.85 80 64 12.2 3875 70 18 — 61 — 80 59 — —6 125 8 8 80 2.69 52 15 44.8 327

Mean 70 10.2 8 81 2.69 78.7 51.5 19.81 385SD 25.5 6 1.4 12.1 0.76 13.1 18.9 13.4 179

AO% Å aortic oxygen saturation; CI Å cardiac index (L/min/m2); FC Å New York Heart Association functional class; LAP Å mean left atrial pressure (mm Hg); PA%Å pulmonary artery oxygen saturation; PAP Å mean pulmonary artery pressure (mm Hg); PVR Å pulmonary vascular resistance (U); RAP Å mean right atrial pressure;SAP Å mean systemic pressure; SOT Å systemic oxygen transport (ml/min/m2).

follow-up 40 months). There were 3 procedure-related deaths. Two occurred within 24 hours ofthe procedure and a third within the first 6 months.The immediate deaths were characterized by pa-tients having severely increased dyspnea, hypoten-sion, and systemic arterial oxygen desaturation andsubsequent cardiac arrest. The patient who diedwithin 6 months was admitted to a local hospitalwith progressive right heart failure and cyanosis,which began after the septostomy and was refrac-tory to all medical treatments.

We compared our results with the published se-ries of Nihill et al5 (14 patients) and Kerstein et al4

(15 patients) (Table II). In all 3 series, the patientswere deemed to be severely symptomatic despite op-timal medical therapy, and the mean pulmonary ar-tery pressure was comparably elevated. However,with respect to other hemodynamic parameters thathave been associated with survival,7 namely, rightatrial pressure and cardiac index, the groups appeardifferent. Our series had patients with the most ad-vanced symptoms (mean right atrial pressure 17 {8 mm Hg, cardiac index 1.7 { 0.65 L/min/m2), withthe series of Nihill et al5 being intermediate (meanright atrial pressure 12 { 8 mm Hg, cardiac index2.04 { 0.51 L/min/m2), and that of Kerstein et al4

the least severe (mean right atrial pressure 11 { 7mm Hg, cardiac index 2.21{ 0.51 L/min/m2) (TableII). These differences were parallel with the magni-tude of increase in cardiac index that occurred fol-lowing the septostomy (from 16% to 58%) and the

amount of decrease in systemic oxygen transport(5% to 27%).

A total of 9 patients (3 in each series) sustainedeither a direct procedure-related death or short-termworsening and death. The hemodynamic features ofthe nonsurvivors revealed that they had lower car-diac indexes and higher right atrial pressures thanthe survivors, but had similar pulmonary artery pres-sures and pulmonary vascular resistances.

j j j

The acute hemodynamic effect of the creationof an atrial septostomy in these patients was to in-crease systemic arterial oxygen transport by in-creasing cardiac index. To the extent that the in-creased oxygen transport results in improved tissueoxygenation and vital organ metabolism, the pa-tient may benefit. In addition, it caused a reductionin right atrial pressure, which could relieve sys-temic venous congestion and allow a reduction inascites and lower extremity edema. In many of thepatients an improvement in symptomatic rightheart failure was clearly a long-term effect of theseptostomy. Importantly, however, the majorphysiologic impact of the septostomy is likely tooccur when the patients are exercising rather thanresting.8,9 In that setting it is expected that right-to-left shunting will increase, which may alloweven better oxygen transport, albeit at the expenseof systemic arterial oxygen saturation. Of note isthat in patients in whom syncope was a disablingsymptom (primarily children), the creation of an

BRIEF REPORTS 371

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TABLE II Comparison of Hemodynamic Changes from Atrial Septostomy

RAP PAP LAP SAP CI PVR AO% SOT

Current series f41% NC NC NC F58% NC f13% F27%Nihill et al5 NC NC — NC F36% — f15% F9%Kerstein et al4 f11% NC F55% NC F15% NC f8% F5%

AO% Å aortic oxygen saturation; CI Å cardiac index; LAP Å mean left atrial pressure; NC Å no change; PAP Å mean pulmonary artery pressure; PVR Å pulmonaryvascular resistance; RAP Å mean right atrial pressure; SAP Å mean systemic pressure; SOT Å systemic oxygen transport.

atrial septostomy appeared to relieve those symp-toms.4 Because the pulmonary vascular bed is un-affected by the procedure, the long-term effects ofan atrial septostomy must be considered to be pal-liative.

However, there are reasons why an atrial septos-tomy is potentially detrimental. Right ventricularfailure and death in many patients with PPH is man-ifested by chronic right ventricular ischemia due toimpaired myocardial perfusion from a reduced cor-onary driving pressure.10 A procedure that lowerssystemic arterial oxygen saturation has the potentialto promote right ventricular ischemia and worsenright ventricular failure. In addition, patients withadvanced pulmonary hypertension can have left ven-tricular diastolic dysfunction, which is manifested byincreasing pulmonary capillary wedge pressures andsymptoms of orthopnea and nocturnal cough.11 Theacute increases in left atrial filling pressure and bloodflow from the atrial septostomy could further elevateleft atrial pressure, cause acute pulmonary edema,and worsen oxygenation.3

Characteristics of the patients who died from theatrial septostomy suggest that the patients who werein severe right ventricular failure, manifested by lowcardiac index and high right atrial pressure, were atgreatest risk for a procedure-related death. In thosepatients there was a large decrease in systemic ar-terial oxygen saturation and an increase in left atrialpressure, suggesting that death could have ensued byeither or both of the above mechanisms. The largedecrease in systemic oxygen saturation is likely re-lated to the high intraatrial gradient. This suggeststhat the size of the septostomy should be kept small,which can be difficult to control.

Based on this collective experience, we believethat atrial septostomy should not be performed in thepatient with severe right ventricular failure and im-pending death. Rather, it seems that the benefit of anatrial septostomy might be best realized if it wereperformed relatively early in the clinical course ofthe disease. Patients who are hemodynamically sta-ble and have reasonable systemic arterial oxygena-tion saturation are more likely to tolerate the proce-dure acutely and more likely to develop long-termadaptations that would make it beneficial over time.

The procedure-related mortality is a concern.Blade septostomy has a risk of serious morbidity(8%) and mortality (2%) and has been recommendedto be performed only by physicians with clinical ex-pertise.12 Combined with the fragile nature of pa-

tients with severe pulmonary hypertension, we be-lieve atrial septostomy should be attempted only ininstitutions with an established track record in thetreatment of advanced pulmonary hypertensionwhere blade septostomy is performed with low mor-bidity. It should not be attempted in patients whohave a large pressure gradient between the right andleft atria, especially in association with a reducedsystemic arterial oxygen saturation.

Currently, prostacyclin has been approved in theUnited States as a treatment of advanced PPH and isassociated with improved exercise tolerance, qualityof life, and survival.13 In our experience, patients pre-fer prostacyclin over atrial septostomy when given achoice, despite the high costs and constant daily dil-igence it requires. However, prostacyclin is notavailable to a large extent worldwide.

Atrial septostomy needs to be studied further asan alternative treatment of advanced PPH when noother option exists.

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