Management of the elderly aortic stenosis patient with low gradient and low ejection fraction

The incidence of aortic stenosis increases with age and thus it occurs frequently in elderly patients. Once severe obstruction has developed, death occurs within 3 years unless the aortic valve is replaced. The results of aortic valve surgery, even in octogenarians, are usually excellent in the absence of comorbidity. The exception to this rule is for the aortic stenosis patient who has low ejection fraction, a low cardiac output and a transvalvular gradient of <30 mm Hg. Such patients have far advanced left ventricular dysfunction and increased operative mortality. However, even these patients may benefit from surgery if they have truly severe aortic stenosis. Because valve area is unreliable at low cardiac outputs, output should be increased pharmacologically in such patients and the valve area recalculated. If the transvalvular gradient increases with output, severe aortic stenosis is present and valve replacement may be beneficial. However, if output increases but gradient does not, only mild stenosis is present and surgery is unlikely to prolong life.     

Low gradient,low ejection fraction aortic stenosis

Opinion statement Low gradient aortic stenosis can be caused by critical aortic stenosis causing left ventricular impairment or by more moderate aortic stenosis coexisting with another cause of left ventricular impairment. The main challenges are to differentiate these two states and then to determine whether the left ventricle is likely to recover after aortic valve surgery. Exhaustive echocardiography is necessary, including the use of dobutamine stress. Guideline criteria for severe aortic stenosis are given in this article. The most secure criteria are mean transaortic pressure difference greater than 30 mm Hg and effective orifice area less than 1.2 cm² during dobutamine stress. However, the presence of left ventricular contractile reserve more closely determines outcome after surgery than do markers of stenosis. Surgery is most clearly indicated if there is severe aortic stenosis and an increase in the systolic velocity integral by greater than 20% during dobutamine infusion. Preoperative catheterization is necessary to determine coronary anatomy, but the aortic valve should not be crossed because of the relatively high risk of death, stroke, pulmonary edema, and cardiogenic shock. In patients judged too ill for immediate surgery, a period of medical resuscitation with diuretics and dobutamine should be considered. Balloon valvotomy is not indicated.     

Prognostic value of preoperative atrial fibrillation in patients with aortic stenosis and low ejection fraction having aortic valve replacement

Aortic valve replacement in severe aortic stenosis (AS) with a low left ventricular ejection fraction (EF) is associated with high perioperative mortality. The aim of this study was to assess the prognostic value of preoperative atrial fibrillation (AF) in patients with AS and low EFs who undergo aortic valve replacement. Eighty-three consecutive patients with severe AS (area <1 cm2) and low EFs (< or =35%) were prospectively included. Perioperative mortality was 12%. Twenty-nine patients (35%) had preexisting paroxysmal or permanent AF. Perioperative mortality was higher in the AF group than in the non-AF group (24% vs 5.5%, p = 0.03). Preoperative AF was identified as an independent predictor of perioperative mortality (odds ratio 7.5, 95% confidence interval 1.19 to 47.06, p = 0.03). Five-year overall survival was lower in the AF group than in the non-AF group (47% vs 77%, p = 0.0017). Associated multivessel coronary artery disease and preoperative AF were identified as 2 independent predictors of overall mortality. In conclusion, in patients with AS with low left ventricular EFs, preoperative AF is associated with higher operative risk and lower postoperative survival. The presence of AF in patients with severe AS and low EFs should be taken into account for operative risk stratification, along with low pressure gradient and associated multivessel coronary artery disease.     

Percutaneous balloon valvuloplasty in patients with severe aortic stenosis and low ejection fraction. Immediate results and 1-year follow-up

The efficacy, morbidity, and 1-year follow-up of balloon aortic valvuloplasty in patients with low ejection fraction (less than 40%) were studied on a consecutive series of 55 patients (mean age, 77 years) treated from September 1985 to February 1987. Because of their age (20 patients greater than 80 years old), poor left ventricular function, and associated diseases, 45 patients were definitely not surgical candidates. Balloon dilatation with 15-23-mm diameter balloon catheters decreased the transvalvular gradient from 66 +/- 24 to 28 +/- 14 mm Hg (p less than 0.001) and increased the valve area from 0.47 +/- 0.15 to 0.83 +/- 0.27 cm2 (p less than 0.001). Immediately after dilatation, ejection fraction mildly increased from 29 +/- 7% to 34 +/- 9% (p less than 0.001) in 38 patients who had undergone a second left ventricular angiogram after dilatation. No significant change in the degree of aortic regurgitation was found after the procedure. Three patients died in hospital (femoral arterial complications in two, septicemia in one). Immediate clinical improvement was noted in 80% of the patients. During the follow-up (mean, 11 months), 22 patients died (heart failure in 15 patients, sudden death in five patients, myocardial infarction in one patient, cancer in one patient). Thirty patients survived, 21 with persistent clinical improvement. Repeat cardiac catheterization was performed at 6 months in 20 patients, of whom eight had recurrence of symptoms. Nine patients had restenosis: their hemodynamic indexes had returned to prevalvuloplasty values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical challenges in accurate assessment of severe aortic stenosis with a special focus on low-gradient aortic stenosis and normal ejection fraction

Aortic stenosis (AS) is one of the most common valvular disorders affecting the aging US population. Although guidelines published by leading cardiac societies outline diagnostic and management strategies for this condition, in daily practice clinicians face dilemmas when trying to confirm the diagnosis of severe AS because of discrepancies in quantitative parameters obtained by echocardiography and cardiac catheterization. More recently, a low-gradient variant of severe AS has been increasingly recognized in the setting of normal ejection fraction. This review focuses on the current clinical challenges of AS diagnosis with a special focus on paradoxical low-flow low-gradient AS in the setting of preserved ejection fraction. We evaluate all aspects of AS quantitation in reference to paradoxical low flow aortic stenosis and discuss newer parameters which may help the clinician reconcile some of the discrepancies of this less understood condition.     

Low gradient aortic stenosis with preserved left ventricular ejection fraction and the role of valve replacement

Background Aortic valve replacement(AVR) improves survival in severe symptomatic aortic stenosis(AS).Yet, in many patients with severe AS, the timing of AVR remains poorly defined. In particular, it is challenging in patients with low mean pressure gradient( 40 mmHg) and severe AS(aortic valve area(AVA) ≤ 1.0 cm~2)with preserved left ventricular(LV) ejection fraction.     

Relation of myocardial mechanics in severe aortic stenosis to left ventricular ejection fraction and response to aortic valve replacement

Decreased left ventricular (LV) longitudinal strain and increased circumferential LV strain have been demonstrated in patients with severe aortic stenosis (AS) and normal LV ejection fraction (LVEF). Biplane myocardial mechanics normalize after aortic valve replacement (AVR). This study objective was to examine LV mechanics before and soon after AVR in patients with AS and LV systolic dysfunction. Paired echocardiographic studies before and soon (7 ± 3 days) after AVR were analyzed in 64 patients with severe AS: 32 with normal LVEF (≥ 50%), 16 with mild to moderate LV dysfunction (LVEF <36% to 50%), and 16 with severe LV dysfunction (LVEF ≤ 35%). Longitudinal myocardial function was assessed from 3 apical views (average of 18 segments) and circumferential function was assessed at mid-LV and apical levels (average of 6 segments per view). Strain, strain rate, and mid-LV and apical rotations were measured using 2-dimensional velocity vector imaging. Before AVR (1) longitudinal strain was low in all patients and correlated with LVEF (ρ = 0.74, p <0.001), (2) mid-LV circumferential strain was supranormal in patients with normal LVEF and low in patients with low LVEF (ρ = 0.88, p <0.001), and (3) apical rotation was highest in patients with mild to moderate LV dysfunction. After AVR, LVEF increased in patients with LV dysfunction and myocardial mechanics partly normalized. In conclusion, compensatory mechanisms (high circumferential strain in patients with preserved LVEF and increased apical rotation in patients with mild to moderate LV dysfunction) were observed in patients with severe AS. Compensatory mechanics were lost in patients with severe LV dysfunction. AVR partly reversed these changes in patients with LV dysfunction.     

3D打印联合ECMO辅助在TAVR治疗低射血分数重度主动脉瓣狭窄中的临床应用

目的 探讨3D打印联合体外膜肺氧合(ECMO)辅助在经导管主动脉瓣置换术(TAVR)治疗低射血分数重度主动脉瓣狭窄中的可行性和有效性。方法 低射血分数重度主动脉瓣狭窄患者10例,于2018年11月—2019年5月在空军军医大学西京医院接受ECMO辅助下经导管主动脉瓣置换术,术前左心室射血分数(LVEF)为(30.3%±10.5%),心功能Ⅳ级(NYHA分级)10例。术前采集患者CT数据,重建患者手术入路,结合3D打印技术制作患者心血管模型辅助术前评估、手术方案确定及术前谈话。结果 10例患者均成功接受TAVR手术,围手术期患者血流动力学指标稳定,手术时间(192.5±30.3) min,DSA照射时间(40.5±3.2) min,ECMO辅助时间(60.5±23.9) min,患者出院后术后1月随访心脏超声提示心功能改善,LVEF为(48.5%±4.3%)。结论 对于低射血分数重度主动脉瓣狭窄的患者在行TAVR时,治疗难度大,3D打印技术为医护人员提供直观模型,辅助医患沟通及术前评估,ECMO辅助可保证患者围手术期的血流动力学稳定,提供有效心肺功能支持,有助于提高手术成功率。     

Aortic stenosis with low preoperative ejection fraction. Long-term postoperative hemodynamic and angiographic studies

Twenty-two patients underwent aortic valve replacement for aortic stenosis with a preoperative ejection fraction less than 45%. Three patients died peroperatively and a fourth patient died 18 months later before the haemodynamic control. The other 18 patients were systematically reinvestigated, on average 16 months after surgery. Sixteen had a remarkable functional improvement and a significant increase in ejection fraction at haemodynamic control: 32 +/- 6% to 61 +/- 8%, p less than 0.001. They were surgical successes (Group I). In this group, the 7 patients with the most severe alteration of ventricular function and an average ejection fraction of: 26 +/- 3%, also improved to near normal function with a postoperative fraction of 62 +/- 11%. There was no significant improvement of the ejection fraction in 2 patients, and they were classified with the fatalities as surgical failures (Group II). The clinical, electrocardiographic, radiological, haemodynamic and angiographic data of these two populations were compared to try and identify preoperative indices of prognostic value. Only the angiographic left ventricular myocardial mass index (LVMI) was significantly higher in Group II (253 +/- 98 g/m2) than in Group I (156 +/- 56 g/m2, p less than 0.05). A discriminating analysis showed that the most important parameters to separate the 2 groups of patients were the LVMI and the thickness of the left ventricular wall. The marked increase of the postoperative ejection fraction in 3/4 of our patients confirmed the clinical value of valvular replacement justifying the indication for surgery in patients with severe aortic stenosis in spite of a severe alteration of left ventricular function.     

Low-level exercise echocardiography fails to elicit left ventricular contractile reserve in patients with aortic stenosis, reduced ejection fraction, and low transvalvular gradient

BACKGROUND: Low-level exercise echocardiography is useful to assess left ventricular (LV) contractile reserve after an acute myocardial infarction. Whether low-level exercise can elicit LV contractile reserve in patients with severe aortic stenosis, reduced LV systolic function and low transvalvular gradient are unknown. Accordingly, the value of low-level exercise to elicit contractile reserve was assessed in these patients using dobutamine administration as the gold standard method. METHODS AND RESULTS: Seventeen patients with severely decreased aortic valve area (0.75 +/- 0.03 cm(2)), reduced LV ejection fraction (35 +/- 2%) and low mean transvalvular gradient (23 +/- 3 mmHg) underwent low-level exercise and dobutamine echocardiography. Ejection fraction increased by 23% (P < 0.001) with dobutamine and decreased by 8% (P = 0.2) with low-level exercise. Left ventricular outflow tract velocity time integral increased from 13 +/- 1 to 16.7 +/- 1 cm (P < 0.001) with dobutamine but did not change with low-level exercise (13 +/- 1 vs. 13.5 +/- 1, P = 0.5). CONCLUSION: Low-level exercise fails to elicit LV contractile reserve in patients with severe aortic stenosis, reduced LV systolic function, and low transvalvular gradient.     

Outcome after valve replacement for severe aortic stenosis associated with reduced left ventricular ejection fraction

BACKGROUND AND AIM OF THE STUDY: Because valve replacement for aortic stenosis (AS) remains a difficult surgical challenge in the presence of left ventricular dysfunction, the immediate and long-term outcomes, and evolution of left ventricular ejection fraction (LVEF) in this setting, were analyzed. METHODS: Forty-three consecutive patients with severe AS (valve area < or =1 cm2) and reduced LVEF (< or =40%) who underwent valve replacement surgery at the authors' institution between April 1998 and December 2003 and were studied retrospectively. RESULTS: Preoperative characteristics included: LVEF 33 +/- 6%, mean transaortic pressure gradient 46 +/- 13 mmHg, and aortic valve area 0.58 +/- 0.15 cm2. Concomitant coronary artery bypass grafting was performed in 15 patients (35%). Perioperative (30-day) mortality was 2.3%, with 39.5% morbidity. During a mean follow up of 33.4 +/- 17.6 months, eight patients died. The Kaplan-Meier estimate of five-year survival was 75.3%. Postoperatively, none of the survivors remained in NYHA functional classes III-IV. The postoperative LVEF assessed in 81.8% of survivors had improved. Multivariate analysis associated improved LVEF with a higher preoperative mean transaortic pressure gradient (p = 0.0009) and a higher preoperative LVEF (p = 0.02). CONCLUSION: Patients with severe AS and reduced LVEF can undergo valve replacement with low perioperative mortality and moderate postoperative morbidity. Good long-term survival with good NYHA functional status and improved LVEF can be obtained.     

Increased mortality after transcatheter aortic valve implantation (TAVI) in patients with severe aortic stenosis and low ejection fraction: A meta-analysis of 6898 patients

Background

There is conflicting evidence regarding the safety and efficacy of transcatheter aortic valve implantation (TAVI) procedures in patients with severe aortic stenosis and low left ventricular ejection fraction (EF). The primary aim of this study was to determine the impact of TAVI on short- and long-term mortality in patients with low EF (EF < 50%); the secondary aim was to analyze the impact of TAVI procedure on EF recovery in the same setting of patients.

Methods and results

Twenty-six studies enrolling 6898 patients with severe aortic stenosis undergoing TAVI procedure were included in the meta-analysis and analyzed for 30-day, 6-month and 1-year all-cause and cardiovascular mortality; a further meta-analysis was also performed in patients with low EF to assess EF changes post TAVI.In low EF patients, both all-cause and cardiovascular short- and long-term mortality were significantly higher when compared to patients with normal EF (30-day-all-cause mortality: 0.13; 95% confidence interval [CI]: 0.01 to 0.25, I² = 49.65, Q = 21.85; 1-year-all-cause mortality: 0.25; 95% [CI]: 0.16 to 0.34, I² = 25.57, Q = 16.12; 30-day-cardiovascular mortality: 0.03; 95% [CI]: − 0.31 to 0.36, I² = 66.84, Q = 6.03; 1-year-cardiovascular mortality: 0.29; 95% [CI]: 0.12 to 0.45, I² = 0.00, Q = 1.88). Nevertheless, in low EF patients TAVI was associated with a significant recovery of EF, which started at discharge and proceeded up to 1-year-follow-up.

Conclusions

Patients with low EF severe aortic stenosis have higher mortality following TAVI compared to normal EF patients, despite a significant and sustained improvement in EF.