THERAPY AND PREVENTION AORTIC VALVE DISEASE Assessment of left ventricular and aortic valve function after aortic balloon valvuloplasty in adult patients with critical aortic stenosis

Preliminary reports have documented the utility of balloon aortic valvuloplasty as a palliative treatment for high-risk patients with critical aortic stenosis, but the effect of this procedure on cardiac performance has not been studied in detail. Accordingly, 32 patients (mean age 79 years) with long-standing, calcific aortic stenosis were treated at the time of cardiac catheterization with balloon dilatation of the aortic valve, and serial changes in left ventricular and valvular function were followed before and after valvuloplasty by radionuclide ventriculography, determination of systolic time intervals, and Doppler echocardiography. Prevalvuloplasty examination revealed heavily calcified aortic valves in all patients, a mean peak-to-peak aortic valve gradient of 77 + 27 mm Hg, a mean Fick cardiac output of 4.6 ± 1.4 liters/min, and a mean calculated aortic valve area of 0.6 + 0.2 cm2. Subsequent balloon dilatation with 12 to 23 mm valvuloplasty balloons resulted in a fall in aortic valve gradient to 39 + 15 mm Hg, an increase in cardiac output to 5.2 + 1.8 liters/min, and an increase in calculated aortic valve area to 0.9 ± 0.3 cm2. Individual hemodynamic responses varied considerably, with some patients showing major increases in valve area, while others demonstrated only small increases. In no case was balloon dilatation accompanied by evidence of embolic phenomena. Supravalvular aortography obtained in 13 patients demonstrated no or a mild (less than or equal to 1 +) increase in aortic insufficiency. Serial radionuclide ventriculography in patients with a depressed left ventricular ejection fraction (i.e., that c55%) revealed a small increase in ejection fraction from 40 + 13% to 46 ± 12% (p < .03). In addition, for the study group as a whole there was a decrease in left ventricular end-diastolic volume index (113 + 38 to 101 + 37 ml/m2, p < .003), a fall in strokevolume ratio (1.49 ± 0.44 to 1.35 + 0.33, p < .04), and no immediate change in left ventricular peak filling rate (2.05 + 0.77 to 2.21 ± 0.65 end-diastolic counts/sec, p = NS). Serial M mode echocardiography and phonocardiography showed an increase in aortic valve excursion (0.5 ± 0.2 to 0.8 ± 0.2 cm, p < .001), a decrease in time to one-half carotid upstroke (80 ± 30 to 60 ± 10 msec, p < .001), and a small decrease in left ventricular ejection time (0.44 ± 0.03 to 0.42 ± 0.02 sec, p < .001). We conclude that percutaneous aortic valvuloplasty in adult patients with calcific aortic stenosis may result in improved aortic valve and left ventricular systolic function. Individual responses to balloon dilatation may vary considerably, with some patients demonstrating dramatic improvement in valvular and ventricular function, while others show little change. Circulation 75, No. 1, 192-203, 1987. From the Charles A. Dana Research Institute and the Harvard-ThornTHE ACCEPTED TREATMENT of symptomatic aordike Laboratory of Beth Israel Hospital, Departments of Medicine (Cartic stenosis in the adult patient is aortic valve replacediovascular Division) and Radiology, Beth Israel Hospital and Harvard Medical School, and the Division of Cardiology, Children's Hospital, ment. In spite of the success of the surgical treatment Harvard Medical School, Boston. of aortic stenosis, however, it is clear that certain paSupported in part from Research training grant HL07394 from the tients fall into a high surgical risk categor." 2 As an USPHS. ry Address for correspondence: Raymond G. McKay, M.D., Cardioalternative nonsurgical treatment for these patients, vascular Division, Beth Israel Hospital, 330 Brookline Ave., Boston, balloon aortic valvuloplasty has been developed, and MA 02215. Received July 8, 1986; revision accepted Sept. 25, 1986. has been documented by our laboratory3 and others4 to 192 CIRCULATION by gest on July 5, 2017 http://ciajournals.org/ D ow nladed from THERAPY AND PREVENTION-AORTIC VALVE DISEASE be successful in treating high-risk patients with calcific aortic stenosis. Although preliminary reports on aortic valvuloplasty have been favorable, the effect of this procedure on left ventricular and aortic valve function has not been studied in detail. Accordingly, the purpose of the present study was to assess the effect of balloon dilatation of the aortic valve on cardiac performance in a group of adult patients with long-standing, calcific aortic stenosis. Methods Study group. Balloon aortic valvuloplasty was attempted at the time of cardiac catheterization in a total of 33 patients (13 men and 20 women) with a mean age of 79 years (range 35 to 93). All patients were symptomatic, with either congestive heart failure, angina, and/or a prior history of syncope. Predominant symptoms included dyspnea on exertion (n = 28), weakness (n = 28), orthopnea (n = 15), angina (n = 15), and presyncope with exertion (n = 7). Fourteen patients at the time of the valvuloplasty study had uncompensated congestive heart failure unresponsive to maximum medical therapy and gross interstitial pulmonary edema on chest x-ray. Twenty-seven patients had previously undergone cardiac catheterization documenting severe aortic stenosis. The cause of aortic stenosis was presumed senile degenerative calcific stenosis in 30, bicuspid calcific stenosis in two, and rheumatic in one patient. Twenty-one patients had mitral regurgitation, with scvere mitral insufficiency noted in nine; one patient had moderate mitral stenosis. Nineteen patients had significant coronary artery disease (greater than 50% luminal narrowing of at least one vessel), including six with severe three-vessel coronary artery disease (two of whom had left main involvement), one with two-vessel coronary artery disease, and 12 with one-vessel coronary artery disease. Two patients had previously undergone coronary bypass surgery. The remaining 14 had normal coronary arteries. Four patients had a previous history of myocardial infarction. Each patient was evaluated by a cardiac surgeon and was offered aortic valve replacement and an estimation of expected surgical risk. All patients subsequently refused surgical intervention. Estimation of surgical risk ranged from 2% to 50%. Major reasons for deferring surgery or for estimation of high surgical risk included advanced age (e.g., greater than 80 years of age, n = 18), severely depressed left ventricular ejection fraction (e.g., less than 40%, n = 10), the need for extensive additional surgery including coronary artery bypass grafting (n = 19) and mitral valve replacement (n = 7), documented or probable malignancy (n = 2), prior bypass surgery (n = 2), severe chronic obstructive pulmonary disease (n = 2), prior attempted aortic valve replacement (n = 1), recent untreated hip fracture (n = 1), history of severe bleeding diathesis (n = 1), morbid obesity (n = 1), and refusal to take long-term anticoagulants (n = 1). Clinical characteristics of the study group are summarized in table 1. All patients gave informed consent for balloon aortic valvuloplasty after being informed of the risks and potential complications of the procedure according to a protocol approved by the Beth Israel Hospital Human Investigations Committee. Aortic valvuloplasty protocol. Each patient was brought to the cardiac catheterization laboratory where a left radial cannula was placed. Twenty-three patients subsequently underwent retrograde left heart catheterization from a percutaneous femoral approach, and nine had retrograde brachial artery catheterization by cutdown; in one patient in whom arterial access was impossible from either the femoral or brachial approach, valvuloplasty was accomplished via a transseptal technique (see below). Right heart catheterization was performed from the femoral or brachial vein with a No. 7F balloon-tipped flotation catheter (Elecath). Left heart catheterization was performed with either a No. 7F pigtail catheter (USCI) or No. 8F Sones catheter (Cordis) and an 0.038 inch, straight-tipped guidewire to cross the aortic valve. In 13 patients, a supravalvular aortogram was obtained before crossing the aortic valve. After placement of left and right heart catheters, measurements were made of systemic arterial, left ventricular, pulmonary arterial, and pulmonary capillary wedge pressures, as well as of left ventricular and pulmonary artery oxygen saturations. Oxygen consumption was measured with a metabolic rate meter (Waters Instruments). Cardiac output was calculated by the Fick method (02 consumption divided by arteriovenous 02 difference), and aortic valve area was determined with the Gorlin formula.5 In the Gorlin formula, antegrade flow across the aortic valve was assumed to be equal to the forward cardiac output, as calculated by the Fick method. Since antegrade flow across the valve is greater than the Fick cardiac output in the presence of aortic regurgitation, valve orifice areas were underestimated. Thus, to the extent that aortic regurgitation increased after valvuloplasty (see below), the increase in aortic orifice area was even larger than indicated by our calculations. After prevalvuloplasty measurements were made, a 300 cm, 0.038 inch exchange guidewire was advanced through the left heart catheter into the left ventricle and the left heart catheter was removed. An additional curve had been placed in the distal tip of the exchange wire to minimize the chance of left ventricular perforation with subsequent balloon inflations and exchanges. Balloon dilatation was performed subsequently, beginning with a 12 mm valvuloplasty balloon (Meditech) in the first five patients and with use of a 15 mm balloon in the remaining 28. The initial valvuloplasty balloon catheter was advanced over the guidewire into the left ventricle, with positioning of the balloon at the aortic valve. At least three inflations were then made with hand injections of a saline/angiovist mixture. The duration of balloon inflation varied (range 10 to 60 sec), depending on each patient's systemic arterial pressure response. After balloon dilatation, a repeat measurement was made of the aortic valve gradient. If a peak-to-peak aortic gradient greater than 50 mm Hg remained, repeat dilatations were performed with a 15 mm valvuloplasty catheter, followed by an 18 mm valvuloplasty catheter, and finally by a 20 mm valvuloplasty catheter. In three patients in whom a gradient greater than 50 mm Hg remained after dilatation with a 20 mm balloon, a 23 mm balloon was also used. After balloon dilatation, the pigtail or Sones catheter was exchanged over the guidewire into the left ventricle, and repeat measurements were made of pressures and cardiac output. The left ventricular catheter was then pulled back to the central aorta, followed by a repeat supravalvular aortogram in the 13 patients who had undergone prevalvuloplasty aortography. In patients who had been catheterized by the femoral route, a No. 12F sheath (UMI) was placed in the right femoral artery at the end of the procedure. Patients catheterized via the brachial approach underwent standard suture repair of the brachial artery and closure of the skin. The right heart catheter was left in place for hemodynamic monitoring in all patients. In one patient in whom arterial access from either the femoral of brachial approach was limited by severe arterial tortuosity and peripheral vascular disease, valvuloplasty was accomplished via a transseptal technique. In this patient, transseptal catheterization was performed with use of a standard Brockenbrough needle and No. 8F Mullins sheath. After transseptal Vol. 75, No. 1, January 1987 193 by gest on July 5, 2017 http://ciajournals.org/ D ow nladed from