**6. Complications**

**5.1. Mortality**

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(P: 0.85)[ 73-74]

kidney disease.

**5.2. Symptom improvement**

studies with a follow-up of more than 1 year [73-74].

substantial improvement in the results obtained with TAVI.

In the multicenter registries and series, mortality was systematically <10% in patients treated using the transfemoral approach and ranged from 11.3% to 16.9% in patients treated using the transapical approach, probably owing to the higher risk profile of the patients treated via the latter route [73-74].At 1-year follow-up, the survival rates were ~80% (75–85%) for the trans‐

As the first of two parallel trials was completed, the results of PARTNER IB showed that TF TAVI was superior to standard therapy in patients not deemed candidates for surgery [73]. The primary endpoint of all-cause mortality was markedly reduced by 46% (P, 0.001). Recently reported 2-year outcomes showed continued encouraging results. At 2 years, the primary endpoint of all-cause mortality was reduced from 67.6% in the standard treatment arm to 43.3% in the TAVI arm (P, 0.001). The PARTNER cohort IA compared TAVI with SAVR and met its non-inferiority endpoint: the all-cause 1-year mortality in the TAVI group was non-inferior to the SAVR group (24.2 vs. 26.8%;P: 0.44; P: 0.001 for non-inferiority) [74]. Some concerns were raised with regard to neurologic events that were somewhat higher with TAVI than SAVR at 30 days (5.5 vs. 2.4%; P: 0.04) and 1 year (8.3 vs. 4.3%; P: 0.04). Although the recently published 2-year results showed that stroke rates were similar for TAVI and SAVR during 1 and 2 years with a hazard ratio of 1.22 (95% CI 0.67–2.23, P: 0.52), the issue of stroke warrants further investigation and should not be underestimated The rate of the composite of all-cause death and stroke was encouragingly nearly identical after TAVI (37.1%) and SAVR (36.4%) at 2 years

Predictors of mortality — Risk factors for early and late mortality were identified in a study of 663 patients undergoing TAVR with CoreValve. Intraprocedural mortality was 0.9 percent. Mortality was 5.4 percent at 30 days and 15 percent at one year. Independent predictors of mortality at 30 days included certain procedural complications (conversion to open heart surgery, cardiac tamponade, major vascular or access site complications) as well as baseline characteristics (left ventricular ejection fraction <40 percent, prior balloon valvuloplasty, and diabetes mellitus). Independent predictors of mortality between 30 days and one year included prior stroke, postprocedural paravalvular leak ≥2+, prior acute pulmonary edema, and chronic

Indeed, in the past few years, 1-year survival rates from some registries have been reported to be ≥80%, and we can expect better survival rates at the 2-year and 3-year follow-ups in the coming years. Importantly, no structural failures of the transcatheter valves have been seen in

In addition to baseline and procedural factors, the learning-curve phenomenon and the improvements in valve prosthesis and delivery catheters have also been associated with a

Three-year follow-up data have been published and are consistent with lasting improvement in cardiac symptoms [72]. While 86% of patients were in NYHA class III or IV at baseline, 93%

femoral approach and ~70% (63–78%) for the transapical approach.

Stroke: The occurrence of stroke is one of the most –fearing complication of TAVI. The most frequent etiology of procedural stroke is likely to be atheroembolism from the ascending aorta or the aortic arh. Other several factors include manipulation of a wire, positioning of device, performance of the balloon aortic valvuloplasty, air embolism, dissection of the arc vessels and inadequate blood flow to brain during rapid pacing. Reported 30 day stroke rate was 3.5 (ranging from 1.2% to 6.7%) [76]. Additionaly Kahlert et al observed that using diffusionweighed MRI has underlined this issue, demonstrating multiple embolic cerebral lesion in all patients after TAVI. Although most of these lesions were clinically silent, silent cerebral infarcts are associated with subtle cognitive change. Efforts have been directed towards prevention of stroke. Procedural anticoagulation to reach a target activated clotting time over 250 s is suggested. Empiric dual antiplatelet therapy is recommended for 3 to 6 months followed by long-term daily low dose aspirin. Additionally less traumatic valve delivery system and embolic protection devices (Embrella embolic deflector system) currently under devolepment might lower the risk of stroke. However some authors have suggested that stroke risk might be lower with transapical access, this has not been a universal finding.

Vascular Complication: Common vascular complication arterial dissection, closure device failure, arterial stenosis, haematoma in the accsess site. Artery avulsion, vessel perforation, annulus rupture represent more severe complications which are fatal if not rapidly treated. In the SOURCE registry, 10.6 % of patients had major vascular complication and major vascular complications were less frequent in the transapical approach (2.4 %) [73-74]. Small vessel diameter, severe atherosclerosis, bulky calcification, and tortusosity are the main determinats of vascular complications. In the future delivery catheter and sheath size will likely decrease which should be associated with reductions in the risk of vascular injury. Additionally, for patients with unsuitable access, alternatives include apical, axillar/subclavian or transaortic approaches, or treatment of iliofemoral lesion with stents or grafts.

Coronary obstruction and myocardial infarction: Coronary ostia obstruction ( especially of the left main coronary artery ) might occur if an obstructive portion of the valve frame or the sealing cuff is placed directly over a coronary ostium however this is very rare but potentially fatal event [77]. Some cases may require immediate coronary angioplasty or coronary artery bypass graft operation. TAVI has been associated with a variable rate of myocardial infarction, ranging from 0% to 16.3% [73-74] Myocardial infarction could be explained by myocardial tissue compression, hypotension due to rapid pacing, atheroembolism and mechanic complication such as coronary ostia obstruction. Additionally myocardial infarction was associated with an increased cardiac mortality at midterm follow up

Heart Block: High grade atrioventricular block and consecutive pacemaker implantation are frequent (especially in CoreValve) complications following TAVI. CoreValve implantation is associated with a need for permanent pacemaker in 20 % of patients compared with in 5 % of patients implanted with the balloon expandable valves [78]. Potential risk factors include aggressive over sizing, low implantation of the prosthesis, small annulus diameter, using CoreValve and the presence of preexisting infranodal block such as RBBB [79, 80].

**7. Surgery**

In 1912, Theodore Tuffier was the first to attempt opening AS using his finger. Russel Brock and then Bailey used dilatators for stenotic aortic valves. Today more than 1000 patients have aortic valve surgery per year and surgery for AS is more common than it is for aortic insuffi‐ ciency [84]. Aortic valve surgery has been improved with the developments of new technolo‐ gies in cardiopulmonary bypass techniques and valve industry. Approximately 2% to 5% of elderly individuals aged 75 years present with signs of severe AS and they are scheduled for elective AVR. AVR is the treatment of choice for patients with severe degenerative AS, offering

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It's obvious that AVR is indicated in all symptomatic patients and asymptomatic patients with severe AS undergoing open heart surgery. The surgery should immediately be programmed if the patient becomes symptomatic. Despite LV dysfunction, the risk of aortic valve replace‐ ment for AS was satisfactory and related to meanaortic gradient and additional coronary artery disease, and long-term survival was related to also coronary disease and cardiac output [86]. 5-year survival for adults after aortic valve replacement is 80-90%. The results of the conven‐ tional surgery for octogenarians are also satisfactory and 5% to 10% of mortality is noted for isolated AVR (2). On the other hand, elderly patients stay longer in the hospitals and intensive care units during the postoperative period [87]. United Kingdom heart valve registry observed 1100 elderly patients (56% women) who underwent AVR that the 30-day mortality was 6.6% [88]. The actuarial survival was 89% at 1 year, 79% at 3 years, 69% at 5 years, and 46% at 8 years. The mortality is rising up to 10% per year for the patient becoming symptomatic. The indications for AVR in patients with AS according to the current ACC/AHA guidelines are listed in Table 2 [89]. Although the surgery for the asymptomatic patients is preferred due to sudden death, surgery for asymptomatic octogenarians is controversial. The complex cardiac

The mortality rate of valve surgery and risk of sudden death without surgery have to be carefully considered. Postoperatively symptoms diminish and quality of life is improved in the majority of patients ≥75 years who had undergone aortic valve surgery, but long term

AVR usually performed under general anesthesia using conventional techniques of open heart surgery with median sternotomy. Minimally invasive surgery has continued to be an evolving concept after the first publication of Cosgrove in 1996 [91] Minimally invasive procedures are associated with acceptable mortality and morbidity rates even in high risk patients. 30-day inhospital mortality was 0.8% for 1,103 minimally invasive aortic valve procedures [92].

The major advantages of minimally access surgeries are improved cosmesis with reduced insicion size, decreased surgical trauma, less pain, better respiratory function and early return

These procedures can be performed through different approaches. These are upper mini sternotomy, transverse sternotomy and right parasternal or anterolateral mini thoracotomy,

both symptomatic relief and a potential for improved long term survival [85].

procedures have high risks for elderly patients.

survival was not affected [90].

to work [92].

Cardiogenic Schock and low cardiac output: This complication may be induced by ischemia, rapid pacing, volume depletion, anesthesia and interruption in cardiac output during valve implantation. Vasopresor agents and intraaortic balloon support to maintain adequate perfusion pressure are often helpful. Rarely elective femoral cardiopulmonary bypass is an option for patients at hemodynamic instability.

Paravalvuler Regurgitation: However paravalvuler aortic regurgitation is common, occurring in about 85 %, Grade > 2 + regurgitation is found in 7-24 % [72,73].Trivial, mild and even moderate degrees of regurgitation seem well tolerated, although grade > 2+ regurgitation associated with increased short and long term mortality [81]. Causes of paravalvular regurgi‐ tation include a heavily calcified annulus,large annulus size, an undersized prosthesis, device failure and inadequate balloon aortic valvuloplasty. Redilatation or implantation of a second, overlapping transcathater valve can often correct the problem.

Acute Kidney Injury: Angiographic contrast injection, hypotension, atheroembolism, peripro‐ cedural blood transfusion might contribute to acute renal failure. The incidence of acute kidney injury after TAVI has been reported with incidence of 8 %. Additionally need for hemodialysis has ranged from 1.4% to 15.7 %, respectively [82]. Predictors of acute kidney injury include hypertension, decrease baseline renal function, previous myocardial infarction, high logistic EuroSCORE and chronic obstructive pulmonary disease [83].

Other Complication: Other significant and very rare complications include aortic rupture, aortic dissection, periaortic hematoma, ventricular or aortic embolization of valve, structural valve failure, cardiac tamponade and acute mitral regurgitation due to mitral valve apparatus damage [73-74].

Valve-in-valve — A valve-in-valve procedure involves catheter-based valve implantation inside an already implanted bioprosthetic valve. This approach may provide an alternative to replacement of a degenerated surgically-implanted valve, or a means of salvaging suboptimal implantation of a catheter-based valve during the initial implantation procedure.

Conclusion: Despite continual technical advancement of TAVI devices and procedures, the combined mortality and morbidity is still high in the range of 5-10%, especially when we are facing a group of high surgical risk patients. In addition TAVR offered no survival benefit compared to standard therapy in patients with an STS score of > 15 % because of high degree of comorbid conditions in these patients. In the future when it is a safer and more reliable procedure and further refinement of the device (i.e. smaller size delivery systems and multiple valve size options) is done, utilization of the procedure in patients with lower surgical risk may be possible.
