Palliation of valvular aortic stenosis by balloon valvuloplasty as preoperative preparation for noncardiac surgery

Asymptomatic Severe Aortic Stenosis and Noncardiac Surgery

The patient with severe asymptomatic aortic stenosis presenting for elective noncardiac surgery poses a unique challenge. These patients are not traditionally offered surgical aortic valve replacement or transcatheter aortic valve replacement given their lack of symptoms; however, they are at increased risk for postsurgical complications given the severity of their aortic stenosis. The decision to proceed with elective noncardiac surgery should be based on individual and surgical risk factors. However, severity of aortic stenosis is not accounted for in current surgical risk factor assessment scoring; therefore, extensive communication with patients and surgical teams is necessary to minimize a patient's risk. A clear intraoperative plan should be designed to manage the unique hemodynamics of these patients, and a discussion should address postoperative placement.

Impact of Aortic Valve Replacement for Severe Aortic Stenosis on Perioperative Outcomes Following Major Noncardiac Surgery

OBJECTIVE

To compare the incidence of major adverse cardiac events and death among severe aortic stenosis patients with and without aortic valve replacement (AVR) before noncardiac surgery.

PATIENTS AND METHODS

We retrospectively evaluated 491 severe aortic stenosis patients undergoing non-emergency/non-urgent elevated-risk noncardiac surgery between January 1, 2000, and December 31, 2013, including 203 patients (mean age, 74±10 years, 63.5% men) with previous AVR and 288 patients (mean age, 77±12 years, 55.6% men) without prior AVR.

RESULTS

The incidence of major adverse cardiac events was significantly lower in the AVR group (5.4% vs 20.5%; P<.001), primarily because of the lower incidence of new or worsening heart failure (2.5% vs 17.7%; P<.001), compared with the non-AVR group. No significant differences were observed between the groups with and without AVR in the incidence of death (2.5% vs 3.5%; P=.56), myocardial infarction (0.5% vs 1.4%; P=.48), ventricular arrhythmia (0.0% vs 0.7%; P=.51), or stroke (0.0% vs 0.7%; P=.51) at 30-days. At a median follow-up of 4.2 (interquartile range,1.3-7.5) years, overall mortality was significantly worse in patients without versus with AVR (5-year rate: 57.0% vs 32.7%; P<.001). Symptomatic patients without AVR (n=35) had the worst outcomes overall, including increased 30-day and overall mortality rates, compared with the AVR-group and asymptomatic non-AVR patients.

CONCLUSION

In patients with severe aortic stenosis, AVR before noncardiac surgery was associated with decreased incidence of heart failure after noncardiac surgery and improved overall survival without differences in 30-day survival, myocardial infarction, ventricular arrhythmia, or stroke. Preoperative AVR should be considered in symptomatic patients for whom the benefit of AVR is greatest.

Aortic Stenosis: What Risks Do the Stresses of Noncardiac Surgery or Pregnancy Pose and How Should They Be Managed?

Studies suggest that patients with aortic stenosis have increased risk in pregnancy and delivery and during anesthesia and surgery, although there are significant degrees of uncertainty as to the exact risks and best way to manage such patients. This article reviews current literature regarding impact of aortic stenosis on pregnancy and anesthesia during noncardiac surgery. There are shortcomings in the scientific evidence. Most of the available studies are observational and often retrospective and therefore there is a great deal of bias. This leads to difficulty in drawing conclusions in terms of how to apply the published information to clinical management.

Core competency review: aortic stenosis and noncardiac surgery

Aortic stenosis (AS) poses a risk of adverse cardiac events for patients undergoing surgical procedures. Perioperative mortality for patients with severe AS is as high as 14%. This review examines the accuracy of the history and physical examination in detecting AS and, subsequently, in assessing severity. The utility of echocardiography is addressed, and the relevant pathophysiology of AS is summarized. We also summarize what is known about perioperative risk for patients with AS.

Efficacy of balloon valvuloplasty in patients with critical aortic stenosis and cardiogenic shock--the role of shock duration

BACKGROUND

Because of limited long-term success, aortic balloon valvuloplasty is considered to be a palliative procedure, including patients at excessive risk for standard therapy-aortic valve replacement-that is, those in cardiogenic shock.

HYPOTHESIS

The study was undertaken to evaluate the outcome of balloon valvuloplasty for critical aortic stenosis complicated by cardiogenic shock.

METHODS

Over a 10-year-period, we followed 14 patients (age 74+/-11 years, range 50-91) presenting in cardiogenic shock and critical aortic stenosis, who underwent valvuloplasty, together with 19 patients with critical aortic stenosis requiring urgent major noncardiac surgery.

RESULTS

In patients in shock, calculated aortic valve area could be increased successfully by at least 0.3 cm2, from 0.38+/-0.09 to 0.81+/-0.12 cm2, with an insignificant increase in cardiac index from 1.89+/-0.33 to 2.01+/-0.41 l/min * m2. In-hospital mortality was 71% (10 patients). Two patients underwent valve replacement within 16 days and survived after 1 year, as did two patients refusing surgery. By multivariate logistic regression analysis, only an interval between onset of shock symptoms and valvuloplasty of > 48 h was significantly associated with fatal outcome (p < 0.01). In those patients requiring noncardiac surgery, this was possible after valvuloplasty in 95% who survived 1 year after hospital discharge. One patient in this group died of pulmonary embolism the day after the procedure.

CONCLUSION

These data support the concept of causal treatment in patients with cardiogenic shock, as well as in the setting of cardiogenic shock and critical aortic stenosis, at the earliest possible convenience.

Anesthetic Considerations in the Patient With Valvular Heart Disease Undergoing Noncardiac Surgery

Valvular heart disease can be an important finding in patients presenting for noncardiac surgery. Valvular heart disease and resulting comorbidity, such as heart failure or atrial fibrillation, significantly increase the risk for perioperative adverse events. Appropriate preoperative assessment, adequate perioperative monitoring, and early intervention, should hemodynamic disturbances occur, may help prevent adverse events and improve patient outcome. This review article aims to guide the practitioner in the various aspects of anesthetic management in the perioperative care of patients with valvular heart disease. The pharmacological approach to optimization of patient outcome with drugs, such as βblockers and lipid-lowering medications (statins), is an evolving field, and recent developments are discussed in this article.

Preoperative and Perioperative Care for Patients With Suspected or Established Aortic Stenosis Facing Noncardiac Surgery

Current medicine has displayed a trend toward less interfering techniques but more invasive surgical approaches in older patients with more comorbidities. In this population, the prevalence of symptomatic cardiac disease including aortic stenosis is increased. More than 25 years have elapsed since severe aortic stenosis was identified as an independent, important risk factor for patients undergoing general anesthesia for noncardiac surgery. Despite impressive advances in anesthesiologic and surgical techniques, morbidity and mortality in patients with severe aortic stenosis remains high. Published study results clearly show that adverse perioperative risk in patients with aortic stenosis depends on the interaction of factors such as the severity of valve disease, concomitant coronary artery disease, and the severity and/or urgency of the surgical procedures. The mainstay of preoperative evaluation remains the obtaining of a comprehensive preoperative medical history and a physical examination, while transthoracic echocardiography is necessary to establish or exclude hemodynamically relevant aortic stenosis in selected patients. Perioperative care is established in patients with asymptomatic aortic stenosis and/or those undergoing low-risk surgery. However, further preoperative testing or aortic valve replacement prior to noncardiac surgery should be discussed individually with the patients awaiting urgent surgical procedures who are at medium or high risk. At this point, decisions should be made in an interdisciplinary manner, including the opinions/wishes of the patient and the patient's family.

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.

Intraoperative valvuloplasty in calcific aortic stenosis: a study comparing the mechanism of a novel expandable device with conventional balloon dilatation

In selected patients with calcific aortic stenosis, balloon valvuloplasty is an intermediate alternative to surgery. The effect of balloon valvuloplasty to increase valve area, however, is limited and the restenosis rate is high during follow-up. To improve the results and reduce the complication rate, a new device for valvuloplasty of calcific aortic stenosis was developed. This system consists of three expandable prongs mounted on a freely movable catheter tip. To evaluate the efficacy of this new device, valvuloplasty was performed in 10 patients with severe aortic stenosis intraoperatively just prior to valve replacement. Comparison was made with the results of conventional balloon dilatation performed in an additional 20 patients during surgery. Using the new device, the relative orifice area increased from 10 +/- 3% before to 20 +/- 6% following intervention. However, in only one patient was a considerable increase of static valve area (greater than 15%) found. The results were comparable to the effect of conventional balloon dilatation, which led to an increase of orifice area from 12 +/- 7% to 24 +/- 10%. With both systems, the best results were achieved in patients with aortic stenosis and significant commissural fusion. In contrast, in bicuspid or tricuspid valves without fused commissures the effect of the intervention was limited. Because complete obstruction of the aortic valve does not occur during dilatation, this new device might be superior to conventional balloon dilatation. Preselection of patients according to the morphology of the valve seems mandatory to improve the success and reduce the complication rate of valvuloplasty in aortic stenosis.

Predictors of event-free survival after balloon aortic valvuloplasty

BACKGROUND

Balloon aortic valvuloplasty was developed as an alternative to aortic-valve replacement in selected elderly patients with aortic stenosis. The use of this procedure is limited, however, by a high incidence of restenosis.

METHODS

Between December 1985 and April 1989, valvuloplasty was performed in 205 patients. We evaluated 40 demographic and hemodynamic variables as univariate predictors of event-free survival by Cox regression analysis and identified independent predictors of event-free survival by stepwise multivariate analysis.

RESULTS

Early hemodynamic results indicated a decrease in the peak transaortic-valve pressure gradient from 67 +/- 28 to 33 +/- 15 mm Hg after valvuloplasty and an increase in aortic-valve area from 0.6 +/- 0.2 to 0.9 +/- 0.3 cm2 (P less than 0.001 for both comparisons). The rate of event-free survival (defined as survival without recurrent symptoms, repeated valvuloplasty, or aortic-valve replacement) was 18 percent over the mean (+/- SD) follow-up period of 24 +/- 12 months (range, 1 to 47). Significant predictors of event-free survival included the left ventricular ejection fraction and the left ventricular and aortic systolic pressure before valvuloplasty, and the percent reduction in the aortic-valve pressure gradient; the pulmonary-capillary wedge pressure was inversely associated with event-free survival. Although the predicted event-free survival rate for the entire patient group was 50 percent at one year (95 percent confidence interval, 43 to 57 percent) and 25 percent at two years (95 percent confidence interval, 19 to 31 percent), the probability of event-free survival at one year varied between 23 and 65 percent when patients were stratified according to three independent predictors: the aortic systolic pressure, the pulmonary-capillary wedge pressure, and the percent reduction in the peak aortic-valve gradient.

CONCLUSIONS

The most important predictors of event-free survival after balloon aortic valvuloplasty were related to base-line left ventricular performance. The best long-term results after valvuloplasty were observed among patients who would also have been expected to have excellent long-term results after aortic-valve replacement.

Acute catastrophic complications of balloon aortic valvuloplasty. The Mansfield Scientific Aortic Valvuloplasty Registry Investigators

Among the initial 492 patients who underwent balloon aortic valvuloplasty as part of the Mansfield Investigational Device Exemption Protocol, 31 (6.3%) had acute catastrophic complications. These included ventricular perforation in nine (1.8%), seven women and two men; six cases (67%) involved serial balloon inflations and seven (78%) also involved dual balloon inflations. In six (67%) of the nine patients perforation was fatal. In four patients studied at necropsy, the perforation involved the base of the lateral left ventricular free wall. Pericardiocentesis was performed in five patients, three of whom survived with (one patient) or without (two patients) operative repair. Acute, severe aortic regurgitation developed in four patients (0.8%), all women. None had significant regurgitation before valvuloplasty; dual balloons were used in two of the four. All three patients who underwent emergency valve replacement survived. A fourth patient died 2 days after valvuloplasty without operative intervention. Fatal cardiac arrest complicated balloon aortic valvuloplasty in 13 patients (2.6%), including 7 with cardiogenic shock and 4 with refractory ventricular arrhythmias. Of the seven with shock, four had been treated with serial balloon inflations; dual balloons were used in three. In two of three patients studied at necropsy, the aortic valve was observed to be congenitally bicuspid. A fatal cerebrovascular accident occurred in two patients (0.4%); it was hemorrhagic in one, embolic in another. Both patients were treated with serial (including one dual) balloon inflations. Limb amputation was required in three patients (0.6%), two women and one man; in two patients amputation was above the knee, in the third patient it was limited to two toes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic valvuloplasty of calcific aortic stenosis with monofoil and trefoil balloon catheters: practical considerations. An evaluation of balloon design and valvular morphology relationship, derived from experimental and clinicopathological observations

In order to evaluate the relation between balloon design (monofoil, trefoil) and valvular configuration, experimental aortic valvuloplasty was performed in four post-mortem hearts with calcific aortic stenosis of various morphology. The degree of obstruction of the aortic orifice was assessed by computed axial tomography during inflation of monofoil 15 and 19 mm and trefoil 3 x 12 mm balloon catheters. We also evaluated the hemodynamic repercussion of balloon inflation (fall in systolic aortic pressure) in four elderly patients with acquired aortic stenosis who underwent a percutaneous transluminal aortic balloon valvuloplasty, with stepwise increasing balloon sizes of 15 mm, 19 mm and 3 x 12 mm, as during our in vitro experiments, and who underwent aortic valve replacement later on. In these patients, we correlated the anatomy of the excised aortic valves with the retrospective analysis of aortic pressure curves recorded during previous valvuloplasty procedures. Our experimental and clinicopathological observations showed that the degree of obstruction of the aortic orifice in post-mortem specimens and the tolerance to balloon inflation in live patients are dependent of the valvular configuration. Although trefoil balloons have the theoretical advantage to avoid complete obstruction of the aortic orifice during inflation, we observed that in presence of a tricuspid configuration, they could be potentially more occlusive than monofoil balloons since each of the 3 individual components of the trefoil balloon occupied the intercommissural spaces while inflated. However, they offered more residual free space when inflated in aortic valves with a bicuspid configuration (i.e. congenitally bicuspid valves or tricuspid valves with one fused commissure). In our opinion, these observations are relevant, since degenerative disease of the aortic valve (i.e. tricuspid valve without commissural fusion) is now recognized as the most common etiology of aortic stenosis in the elderly.

Palliative percutaneous aortic balloon valvuloplasty before noncardiac operations and invasive diagnostic procedures

Percutaneous aortic balloon valvuloplasty (PABV) is useful in palliating symptoms of severe aortic stenosis in patients who are not candidates for aortic valve replacement. In 15 patients who had severe aortic stenosis and a contraindication to aortic valve replacement, PABV was performed before a noncardiac procedure, in an attempt to improve their hemodynamics and reduce the risks associated with the operation or preoperative diagnostic test. The mean aortic gradient was reduced from 58.1 +/- 6.0 mm Hg to 32.2 +/- 4.0 mm Hg (P less than 0.0002), and the aortic valve area was increased from 0.49 +/- 0.04 cm2 to 0.85 +/- 0.10 cm2 (P less than 0.0002). Complications associated with PABV included left ventricular perforation in three patients (which resulted in death in one of them), transient congestive heart failure in one, and development of femoral pseudoaneurysms in one. After PABV, nine patients underwent the planned surgical procedure under general anesthesia without complications. Five patients underwent surgical diagnostic procedures after PABV that resulted in a change in treatment strategy. Three of these patients required no further treatment, and two required resection of the colon for bleeding, which was preceded by aortic valve replacement. This study demonstrates that PABV may be useful in reducing the risks of noncardiac procedures in selected patients with severe aortic stenosis who are otherwise not candidates for aortic valve replacement.