Percutaneous balloon valvuloplasty for critical aortic stenosis: a bridge to safer noncardiac surgical procedures

The treatment of aortic stenosis: is valvuloplasty ever an alternative to surgery?

The desire to extend the principle of balloon angioplasty to cardiac valve disease is understandable and commendable. Aortic valvuloplasty is associated, however, with an excessive complication rate, as reported by the Mansfield Scientific Aortic Valvuloplasty Registry (20.5% overall, including a 4.9% death rate within 24 hours and an additional 2.6% rate within 7 days for a 7.5% 1-week mortality). In contrast, the operative mortality for aortic valve replacement now ranges from 3%-5%, with perioperative complications far less than the one in five associated with valvuloplasty. Even if the two procedures had equivalent morbidity and mortality rates, the high incidence of restenosis (30%-60% range at 6 months) for the balloon technique precludes its widespread use for aortic stenosis. Despite the poor mid- and long-term results for balloon valvuloplasty, the procedure may have limited application in some clinical situations. Indeed, there are patients with concomitant systemic illnesses or advanced age ( greater than 80 years) who would not be good surgical candidates. In particular, valvular balloon dilation may be useful in bridging a seriously ill patient to a condition more favorable for replacement therapy. With few exceptions, however, valve replacement remains the gold standard for treatment of adult aortic stenosis.

Percutaneous balloon aortic valvuloplasty. Acute and 30-day follow-up results in 674 patients from the NHLBI Balloon Valvuloplasty Registry

BACKGROUND

Percutaneous balloon aortic valvuloplasty has been used as a therapeutic option for relief of valvular stenosis. This study describes patients undergoing initial percutaneous aortic balloon valvuloplasty enrolled in the National Heart, Lung, and Blood Institute (NHLBI) Balloon Valvuloplasty Registry.

METHODS AND RESULTS

Extensive baseline procedural and postprocedural data were tabulated in 674 patients during a 24-month period. Functional status was captured using standard methods and an overall functional scoring system. Complications were defined and divided into procedural, acute (within 24 hours), in-hospital, and within 30 days of the procedure. The patient population was elderly and symptomatic, with 83% greater than 70 years of age. New York Heart Association functional class (FC) III or IV congestive heart failure (CHF) was present in 76%, syncope or presyncope was present in 34%, and Canadian Heart Association class III or IV angina was present in 23%. Using an overall functional scoring system (0-100), 54% exhibited scores less than 50. Comorbid disease was common. Forty-five percent possessed at least one serious noncardiac disability as a reason for valvuloplasty. Eighty percent of those seen by a cardiothoracic surgeon were believed inappropriate for aortic valve replacement. Hemodynamically, the aortic valve area increased from 0.5 +/- 0.2 cm2 to 0.8 +/- 0.3 cm2 (p less than 0.0001), accompanied by a fall in mean and peak aortic valve gradient from 55 +/- 21 and 65 +/- 28 mm Hg to 29 +/- 13 and 31 +/- 18 mm Hg, respectively (both p less than 0.0001). Small but significant increases were observed in cardiac output, heart rate, and mean aortic pressure with minor declines in the pulmonary artery (PA) systolic and left ventricular (LV) end-diastolic pressure. One hundred sixty-seven (25%) experienced at least one significant complication within 24 hours, and 211 (31%) experienced a significant complication before discharge. Complications before hospital discharge included the need for transfusion (23%), vascular surgery (7%), cerebrovascular accident (3%), other systemic embolus (2%), myocardial infarction (2%), acute tubular necrosis (1%), or cardiac surgery (1%). Seventeen (3%) patients died during the procedure; 16 of those were due to cardiac causes. By hospital discharge, there was an additional 52 total deaths; 37 were due to cardiovascular causes. Between hospital discharge and 30 days, 23 additional deaths occurred; 18 were due to cardiac disease. At 30 days, therefore, there was a grand total of 92 (14%) deaths; 71 (11%) were due to cardiovascular-related causes. Univariate and logistic regression analysis of mortality revealed that death was most frequent in patients suffering multiorgan failure and poor LV systolic function. Thirty-day mortality was associated with a predefined high-risk subset of hypotension and NYHA class IV CHF (risk ratio, 4.4), blood urea nitrogen (BUN) greater than 30 mg/dl (risk ratio, 3.7), use of an antiarrhythmic (risk ratio, 2.9), and cardiac output less than 3.0 l/min (risk ratio, 2.4). Of the survivors (86%) at 30 days, symptomatic improvement was generally present. Seventy-five percent experienced at least one functional class improvement in CHF, and 53% experienced at least a quartile improvement in overall functional status score.

CONCLUSIONS

These data reveal that percutaneous aortic balloon valvuloplasty in an elderly and debilitated population can be done with low mortality but substantial morbidity. Mortality is greatest in patients with multiorgan failure resulting from poor cardiac output. In patients with reasonably preserved LV function who are otherwise inappropriate surgical candidates because of comorbid factors, survival and early improvement in symptomatic status are frequently observed after percutaneous aortic valvuloplasty.