Safety of remote aortic valve replacement after prior coronary artery bypass grafting

Previous coronary artery bypass graft is not associated with higher mortality in transcatheter aortic valve replacement: systemic review and meta-analysis

Introduction: Patients with previous coronary artery bypass graft (CABG) are usually considered as high-risk groups perioperatively. Recent studies suggest that previous CABG is not associated with mortality in patients with severe aortic stenosis (AS) who underwent transcatheter aortic valve replacement (TAVR). However, systematic review and meta-analysis of the literature has not been done. Thus, we conducted this systematic review and meta-analysis to assess the association between previous CABG and mortality in patients undergoing TAVR.Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to July 2018. Included studies were published prospective or retrospective cohort studies that evaluated the effects of previous CABG status on mortality risk among patients undergoing TAVR. Data from each study were combined using the random-effects, generic inverse variance method of DerSimonian and Laird to calculate risk ratios and 95% confidence intervals.Results: Eleven cohort studies from March 2010 to April 2018 were included in this meta-analysis involving 7299 subjects with severe AS undergoing TAVR (1890 with and 5409 without previous CABG). Previous CABG was not associated with all-cause mortality (pooled risk ratio = 0.96, 95% confidence interval: 0.80-1.16, p=.66, I²=21%) and cardiovascular (CV) mortality (pooled risk ratio = 1.23, 95% confidence interval: 0.64-2.39, p=.72, I²=35%).Conclusions: Previous CABG is not associated with either all-cause mortality or CV mortality in patients with severe AS undergoing TAVR. TAVR should be considered as an alternative or first-line treatment option among severe AS patient, regardless of previous CABG status.

Outcomes of Transfemoral Transcatheter Aortic Valve Implantation in Patients With Previous Coronary Bypass

Patients with previous coronary artery bypass grafting (CABG) are considered to be at increased perioperative risk for a redo cardiac operation. In the era of transcatheter aortic valve implantation (TAVI), these patients constitute a considerable portion of those with severe aortic stenosis referred for TAVI. We evaluated the impact of previous CABG on transfemoral TAVI outcomes. Patients with severe symptomatic aortic stenosis (n = 515) who underwent transfemoral TAVI were divided according to the presence of history of CABG. Patients with previous valvular surgery were excluded (n = 12). TAVI clinical end points and adverse events were considered according to the Valve Academic Research Consortium 2 definitions. Survival was estimated using Cox regression models at the enter mode with the dependent variable defined as all-cause mortality. Of the total 503 patients who underwent TAVI, 91 (18.1%) had previous CABG. At baseline, patients with previous CABG were younger (80.8 vs 83.1 years, p <0.001), mostly men (85% vs 35%, p <0.001), had more cardiac and vascular co-morbidities, higher mean logistic EuroSCORE (32.8 vs 22; p <0.001), lower ejection fraction (53% vs 56%, p <0.001), and lower AV gradients and larger valve area. At a mean follow-up of 636 days, the overall Valve Academic Research Consortium 2-adjudicated end points did not differ. No differences in mortality were observed at 30 days, 6 months, and 1 year after TAVI (hazard ratio 1.34, p = 0.55, Cox regression). We conclude that patients with previous CABG who underwent TAVI do not have increased risk of periprocedural complications or mortality, although having distinct clinical features compared with the total TAVI population.

Changing strategy for aortic stenosis with coronary artery disease by transcatheter aortic valve implantation

Coronary artery disease (CAD) is combined with aortic stenosis (AS) in 40-50 % of patients with typical angina. Recently, transcatheter aortic valve implantation (TAVI) has changed the guideline for AS in patients with high comorbidity. At the same time more than 60 % of isolated CABG has been performed without cardiopulmonary bypass in Japan. CABG is recommended and should be considered in patients with primary indication for AVR and luminal stenosis >70 % in major coronary arteries and the left internal thoracic artery (LITA) by guidelines. AVR is indicated for severe AS undergoing CABG. It is generally accepted to perform AVR for moderate AS at the time of CABG by valve guidelines. However, prophylactic AVR for moderate AS associated with CABG may increase the early operative risk and expose the patients to postoperative long-term valve related complications. AVR after previous CABG poses potential risk for mortality and morbidity. The presence of patent ITA is a significant risk of its injury and difficulty of myocardial protection during aortic cross-clamping. Therefore, at present, for severe AS previous CABG with patent ITA should be one of the definite indications of TAVI. Rationale of TAVI in patients with severe AS and CAD has not been clearly delineated. The safety of TAVI irrespective of the extent and anatomy of CAD is still controversial. PCI is not appropriate before TAVI in high-risk patients with CAD. In the near future hybrid TAVI will be realistic considering least operative mortality and morbidity in high-risk patients.

Aortic valve replacement for stenosis with or without coronary artery bypass grafting after 2 previous isolated coronary artery bypass grafting operations

Aortic valve replacement following an earlier coronary artery bypass grafting (CABG) procedure is fairly common. When this situation occurs, the type of valve dysfunction is usually stenosis (with or without regurgitation), and whether it was missed at the time of the earlier CABG or developed subsequently is usually unclear. We attempted to determine the survival in patients who had had aortic valve replacement after 2 previous CABG procedures. We describe 12 patients who had aortic valve replacement for aortic stenosis; rather than one previous CABG operation, all had had 2 previous CABG procedures. Only one patient died in the early postoperative period after aortic valve replacement, and the remaining 11 were improved substantially: all have lived at least 11 months, and one is still alive at over 101 months after aortic valve replacement. Aortic valve replacement remains beneficial for most patients even after 2 previous CABG procedures.

Beating heart continuous coronary perfusion for valve surgery: what next for clinical trials?

Prior to the introduction of cardioplegia, beating heart continuous coronary perfusion (BHCCP) was the only available method of myocardial protection. Currently, cardiac surgery on cardiopulmonary bypass with cardioplegic arrest is the gold standard strategy. Cardioplegic arrest provides an easier and safer way to operate on a still heart. It enables the performance of a broader range of cardiac procedures, and avoids the potential difficulties of continuous perfusion on a beating heart. Despite the overall effectiveness and safety of cardioplegia, some adverse effects remain, mainly due to the insult of ischemia, which results in ischemic reperfusion injury. As a result BHCCP has seen a revival as an alternative to cardioplegia for performing complex valvular surgery. Increasing experience reporting safety and efficacy of BHCCP is being published. However, despite the reported advantages, current available evidence validating safety and efficacy of BHCCP is controversial. This article provides an overview of BHCCP highlighting the current best available evidence supporting this strategy, concerns, controversies and potential areas for further research.

Cusp shaving for concomitant mild to moderate rheumatic aortic insufficiency

BACKGROUND

The aim of this study was to assess the early and mid-term results of patients who underwent cardiac operations due to cardiac pathologies other than aortic valve (AV) disease, but also had mild-to-moderate aortic valve insufficiency that was repaired during the same session.

METHODS

A total of 43 patients who underwent AV repair for mild-to-moderate aortic insufficiency between January 2003 and February 2009, in addition to the procedure performed for their main pathology necessitating the surgical intervention, were included in the present study. Cardiac function was evaluated, before and after the operation.

RESULTS

Hospital mortality rate was 4.6% (two patients). After the operations, significant improvements were observed in aortic insufficiency (0.57 +/- 0.50 vs. 2.86 +/- 0.48, p = 0.001), New York Heart Association class (1.08 +/- 0.28 vs. 3.03 +/- 0.44, p = 0.001), and left atrial diameter (47.37 +/- 9.28 vs. 42.35 +/- 7.02; p = 0.001). However, left ventricular end diastolic and end-systolic diameters remained unchanged. Two patients were re-operated for AV disease during the follow-up period; thus, at five years, the rate of freedom from re-operation due to AV pathology was 90.7 +/- 6.3%.

CONCLUSIONS

Cusp shaving is a feasible option that can be performed with low risk for concomitant aortic insufficiency.

Three-dimensional printing creates models for surgical planning of aortic valve replacement after previous coronary bypass grafting

PURPOSE

Resternotomy for aortic valve replacement in patients with previous coronary artery bypass grafting and an internal mammary artery graft may be a surgical problem. Thus, we are exploring the effect of using rapid prototyping techniques for surgical planning and intraoperative orientation during aortic valve replacement after previous coronary artery bypass grafting (CABG).

DESCRIPTION

As a proof of concept, we studied a patient who had undergone CABG 5 years earlier. At that time the patient received a left internal mammary artery graft to the left anterior descending artery and a venous graft to the right coronary artery. Now the patient required aortic valve replacement due to symptomatic aortic valve stenosis. The left internal mammary artery bypass and the right coronary artery bypass were patent and showed good flow in the angiography. The patient was examined by 128-slice computed tomography. The image data were visualized and reconstructed. Afterwards, a replica showing the anatomic structures was fabricated using a rapid prototyping machine.

EVALUATION

Using data derived from 128-slice computed tomography angiography linked to proprietary software, we were able to create three-dimensional reconstructions of the vascular anatomy after the previous CABG. The models were sterilized and taken to the operating theatre for orientation during the surgical procedure.

CONCLUSIONS

Stereolithographic replicas are helpful for choosing treatment strategies in surgical planning and for intraoperative orientation during reoperations of patients with previous CABG.

Aortic valve replacement in patients with mild or moderate aortic stenosis and coronary bypass surgery

PURPOSE

To assess whether there is survival benefit for patients with mild or moderate aortic stenosis if they undergo aortic valve replacement at the time of coronary artery bypass surgery.

METHODS

From 1985 to 1995 we evaluated all patients at our institution who underwent coronary artery bypass surgery and who had the echocardiographic diagnosis of mild (mean gradient <0 mm Hg and/or valve area >1.5 cm(2)) or moderate (mean gradient > or =30 and < or =40 mm Hg and/or valve area >1.0 < or =1.5 cm(2)) aortic stenosis. Using propensity analysis, survival was compared between 129 patients who underwent coronary artery bypass surgery alone and 78 patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement.

RESULTS

Perioperative mortality was similar among patients who underwent coronary artery bypass surgery alone compared with patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement. By Kaplan-Meier analysis, 1-year and 8-year survival were better at 90% and 55% for patients who underwent concomitant coronary artery bypass surgery and aortic valve replacement compared with 85% and 39% for patients who underwent coronary artery bypass surgery alone (P <0.001). This benefit was limited to patients with moderate aortic stenosis (propensity-adjusted relative risk = 0.43; 95% confidence interval: 0.20 to 0.96; P = 0.04).

CONCLUSION

Concomitant aortic valve replacement at the time of coronary artery bypass surgery for mild or moderate aortic stenosis appears to convey a survival advantage for patients with moderate aortic stenosis but not for those with mild aortic stenosis.

Reverse "U" aortotomy for aortic valve replacement after previous coronary artery bypass grafting

The presence of patent vein grafts on the proximal aorta may give technical difficulties during exposure to aortic valve replacement after previous coronary artery bypass operations. A tongue or reverse "U" shape aortotomy allows excellent exposure of the aortic valve and antegrade cardioplegic administration without mobilizing vein grafts. This approach may facilitate uni- or bidirectional aortic root enlargement in patients with small aortic root.

When is concomitant aortic valve replacement indicated in patients with mild to moderate stenosis undergoing coronary revascularization?

Mild to moderate aortic stenosis is a common finding in patients presenting for coronary artery bypass grafting (CABG), and its management is controversial. However, review of available data suggests a surgical strategy for these patients. Recent data demonstrate that 1) progression of aortic stenosis is more rapid in those with leaflet calcification; 2) the addition of aortic valve replacement to CABG in patients with mild to moderate stenosis does not increase hospital mortality when compared with bypass surgery alone; 3) hospital mortality for aortic valve replacement after previous bypass surgery has declined in recent years; 4) aortic valve replacement places the patient at risk for prosthesis-related complications; 5) the limited 10-year survival (competing risk of death) leaves only a minority of individuals with mild aortic stenosis alive and eligible for aortic valve replacement 10 years after bypass surgery; and 6) combined aortic valve replacement and CABG confers a survival benefit in those with moderate aortic stenosis but not in those with mild aortic stenosis. Therefore, in the coronary artery bypass patient with moderate aortic stenosis, leaflet calcification, and life expectancy greater than 5 years, concomitant aortic valve replacement is advised. In contrast, aortic valve replacement is rarely indicated in those with mild aortic stenosis.

Aortic valve replacement in patients with previous cardiac surgery

BACKGROUND

Whether minimally diseased aortic valves should be replaced during other necessary cardiac operations remains controversial. Part of the decision-making process in that issue revolves around the risks of subsequent aortic valve replacement. This study evaluated the results of aortic valve replacement in patients following prior cardiac surgery.

METHODS

From February, 1984 through December, 2001 first-time aortic valve replacement was performed in 132 consecutive patients who had previous cardiac surgery utilizing cardiopulmonary bypass. Of those patients 89 (67%) had aortic valve replacement at a mean of 8.3 years after prior coronary artery bypass grafting, and 43 (33%) had aortic valve replacement at a mean of 13.0 years after previous procedures other than myocardial revascularization. Hospital records of all patients were retrospectively reviewed.

RESULTS

Early complications included operative mortality in six (6.7%) of the patients with prior coronary grafting and no mortality in the group with other prior operations. Patients having prior coronary grafting had more nonfatal complications than those with other previous procedures.

CONCLUSIONS

Aortic valve replacement in patients following previous cardiac surgery can be accomplished with acceptable mortality and morbidity. Routine replacement of aortic valves that are minimally diseased during coronary artery bypass grafting may not be warranted.

Management of Mild Aortic Stenosis During Coronary Artery Bypass Surgery:

BACKGROUND

"Prophylactic" aortic valve replacement (AVR) in patients with asymptomatic, mild-to-moderate aortic stenosis (AS) at the time of CABG is controversial. In 1994, we reported our initial experience involving 44 patients and have now updated our series in an attempt to further evaluate outcomes.

METHODS

Between January 1992 and July 2001, 100 consecutive patients underwent reoperative AVR following previous CABG. Forty patients had their initial surgery at the Brigham & Women's Hospital (BWH) and 60 patients had their coronary surgery elsewhere. None of the 40 BWH patients had a mean valve gradient greater than 25 mmHg at the time of CABG.

RESULTS

The mean time interval from CABG to AVR for the entire group was 9.0 years (range: 1.4-21 years). Overall operative mortality (OM) was 7% including 5 deaths (10.2%) among 49 patients requiring additional CABG at the time of AVR and 2 deaths (3.9%) among 51 patients without additional coronary artery intervention. This OM rate was a notable decrease from our earlier report of 18.2% (P = 0.07). Furthermore, operative mortality decreased progressively from 15.4% in 1992-1993 to 0% in 2000-2001 (P = NS).

CONCLUSION

The OM of reoperative AVR following CABG has fallen in recent years. Given the relevance of newer techniques and approaches, it may be reasonable to adopt an expectant management approach in patients with asymptomatic mild-to-moderate AS (i.e., mean systolic gradient less than 25 mmHg) at the time of CABG.

Can progression of valvar aortic stenosis be predicted accurately?

BACKGROUND

It was the aim of the present study to elaborate criteria for the assessment of rapid hemodynamic progression of valvar aortic stenosis. These criteria are of special importance when cardiac surgery is indicated for other reasons but the established criteria for aortic valve replacement are not yet fulfilled. Such aspects of therapeutic planing were mostly disregarded in the past so that patients had to undergo cardiac reoperation within a few years.

METHODS

Hemodynamic, echocardiographic, and clinical data of 169 men and 88 women with aortic stenosis, aged 55.2 +/- 15.7 years at their first and 63.4 +/- 15.6 years at their second cardiac catheterization, were analyzed.

RESULTS

The progression rate of aortic valve obstruction was found to be dependent on the degree of valvar calcification ([VC] scoring 0 to III) and to be exponentially correlated with the aortic valve opening area (AVA) at initial catheterization. Neither age nor sex of the patient nor etiology of the valvar obstruction significantly influence the progression of aortic stenosis. If AVA decreases below 0.75 cm(2) with a present degree of VC = 0, or AVA of 0.8 with VC of I, AVA of 0.9 with VC of II, or AVA of 1.0 with VC of III, it is probable that aortic stenosis will have to be operated upon in the following years.

CONCLUSIONS

The present data indicate that for clinical purposes and planning of valvar surgery the progression of asymptomatic aortic stenosis can be sufficiently predicted by the present aortic valve opening area and the degree of valvar calcification.

Management of asymptomatic aortic stenosis in patients undergoing coronary artery bypass grafting

This study compared the outcomes of combined coronary artery bypass grafting (CABG)/aortic valve replacement (AVR) and CABG alone in patients with moderate aortic stenosis and determined the possible indications for AVR at the time of CABG. Between December 1988 and January 2001, in Tenri Hospital, 41 patients with aortic stenosis underwent CABG: 26 patients underwent the combined procedure and 15 patients underwent CABG alone. The patients who underwent CABG alone were separated them into 2 groups on the basis of the results of annual echocardiography: the rapid progression group, defined by an increase of deltaP by >/=10 mmHg/year, and the slow progression group. Of the 15 patients who underwent CABG alone, the probability of survival at the end of the study in 2001 was 92% at 5 years and 74% at 10 years, and the respective event-free rates were 65% and 50%. Patients less than 70 years old and who were in the rapid progression group had a greater risk for re-operation. The study suggests that patients younger than 70 years old with risk factors for rapid progression should undergo CABG/AVR, and conversely, those older than 70 years old without the risk factors can undergo CABG only.

Aortic valve surgery after previous coronary artery bypass grafting with functioning internal mammary artery grafts

BACKGROUND

Aortic valve surgery after coronary artery bypass grafting (CABG) in the setting of patent pedicled internal mammary artery (IMA) grafts poses a high risk because of the underlying ischemic and valve disease. Unlike mitral valve surgery or CABG, in which aortic clamping (AoX) may be optional, aortic valve surgery uniformly requires AoX unless circulatory arrest is used. Management of the IMA graft in these circumstances has traditionally involved dissection and clamping to prevent regional myocardial warming and cardioplegia "washout" during AoX. An alternative strategy involves avoiding dissection of the IMA, leaving the IMA graft open and establishing moderate-to-deep hypothermia during AoX and cardioplegic arrest. To date, no study has been published documenting the safety and efficacy of the latter practice.

METHODS

A total of 94 patients who had patent IMA graft and underwent aortic valve surgery under AoX and cardioplegia between April 1992 and March 2001 were analyzed. The IMA was avoided and left open during AoX, and the patients were cooled systemically (median 20 degrees C). Patients ranged in age from 55 to 90 years (median 73.5 years). Ejection fraction was 15% to 83% (median 50%). Of the patients, 18 (19%) underwent minimally invasive upper hemi-resternotomy. Analysis for predictors of outcome was performed.

RESULTS

The operative mortality, perioperative myocardial infarction (MI), and stroke rates were 6.4%, 7%, and 11%, respectively. No significant independent predictors of operative mortality or MI could be identified in the multivariate analysis, although a trend was shown for operative mortality with urgent procedures and patients requiring concomitant surgery of the ascending or arch aorta or aortic root. Advanced age and prolonged cardiopulmonary bypass predicted stroke in the multivariate analysis. There were five (5%) IMA injuries, all occurring during reentry or mediastinal dissection, but none in the subgroup of patients who underwent minimally invasive procedures. All patients survived.

CONCLUSIONS

Patients undergoing aortic valve surgery after CABG in the presence of patent IMA represent a potentially high-risk group. Because AoX is almost uniformly required, a decision regarding the management of the IMA pedicle is needed. We have found that leaving the IMA undissected and unclamped is a reasonable strategy, provided that systemic cooling for myocardial protection is established to prevent regional warming and to compensate for cardioplegia washout effect during AoX.

Repair of moderate aortic valve lesions associated with other pathology: an 11-year follow-up

OBJECTIVES

The presence of moderate aortic valve (AV) lesions associated with other pathologies that require surgery presents a problem since ignoring or replacing the valve seems unsatisfactory. AV repair can be an attractive alternative if shown to perform satisfactory.

METHODS

To evaluate this possibility, all consecutive AV patients who underwent operation between July 1988 and July 1999 were reviewed. Out of 1764 AV patients, 239 (14%) underwent repair and 86 (study group) had moderate lesions associated with mitral (73), tricuspid (33), coronary disease (5) and others (8). Mean age was 28 years (range 2--66); 78% were rheumatic, 71% were in sinus rhythm and 71% in NYHA class III--IV.

RESULTS

There were seven hospital deaths (8%) and three patients were lost to follow-up (95% complete). Late mortality was 8% and 10-year actuarial survival was 86 +/- 4.5% (excluding hospital mortality). There were four (5%) embolic events (actuarial freedom 94 +/- 3.5%). Twenty-one patients required reoperation with two mortalities. The AV was not touched in five patients. In the remaining 16, the AV was replaced. Only one patient had isolated AV replacement while in all others, additionally, the mitral, tricuspid, or both required surgery. All reoperated patients had rheumatic etiology. Actuarial freedom from AV dysfunction at 8 years was 68 +/- 7.5%.

CONCLUSIONS

Repair of associated moderate AV lesion is worth considering even in a predominantly young rheumatic population.

Management of patients with mild aortic stenosis undergoing coronary artery bypass grafting

BACKGROUND

The management of mild aortic stenosis during coronary artery bypass grafting remains controversial.

METHODS

We reviewed the medical records of consecutive patients between January 1, 1977, and December 31, 1994, to identify 51 patients with mild aortic stenosis who underwent isolated coronary artery bypass grafting (group A), and 19 patients with mild aortic stenosis who underwent combined coronary artery bypass grafting and aortic valve replacement (group B). Patients with more than moderate aortic regurgitation were excluded. Preoperative angiograms were reviewed to assess the severity of calcification and restricted mobility of the aortic cusps.

RESULTS

In group A there were 11 deaths and 8 subsequent aortic valve replacements; in group B there were 5 deaths and 3 prosthetic valve-related complications. There was no difference in event-free survival between the two groups after adjusting for the difference in age. Among group A patients, the initial transvalvular gradient (p = 0.0005) and aortic valvular calcification (p = 0.06) identified patients who demonstrated progression to severe aortic stenosis during follow-up.

CONCLUSIONS

Our data suggest that routine aortic valve replacement during coronary artery bypass grafting in patients with mild aortic stenosis is not indicated, but concomitant aortic valve replacement may be appropriate in patients with higher transvalvular gradients and calcified valves.

The natural history and rate of progression of aortic stenosis

One of the challenges in clinical cardiology is to determine the optimal time of valve replacement surgery in patients with aortic stenosis. To meet this challenge, one requires an accurate knowledge of the natural history and rate of progression of the disease. This review will summarize the natural history of aortic stenosis in terms of symptoms, mortality, and stenosis progression.

Previous coronary artery bypass grafting is not a risk factor for aortic valve replacement

BACKGROUND

The risk of aortic valve replacement (AVR) after previous coronary artery bypass grafting (CABG) is controversial. Its magnitude influences the threshold for recommending this procedure and has been cited in arguments regarding the optimal management of mild aortic stenosis at primary CABG. We therefore reviewed our experience with reoperative AVR +/- CABG and the primary combined procedure.

METHODS

Between January 1, 1985, and June 30, 1996, 427 patients underwent primary AVR+CABG, and 52 underwent AVR +/- CABG after prior CABG. Demographics, operative characteristics, and operative results were compared between groups. Data for all patients were pooled and analyzed collectively for risk factors influencing mortality.

RESULTS

The extent of native coronary artery disease and the incidence of prior myocardial infarction and stroke were greater in the reoperative group. Aortic cross-clamp and cardiopulmonary bypass times were slightly shorter, and fewer distal anastomoses were performed in the reoperative group. Operative mortality (primary group, 6.3% versus reoperative group, 7.4%) and morbidity were similar. Stepwise multivariate logistic regression analysis identified age, perioperative myocardial infarction, intraaortic balloon support, ventricular arrhythmia, perioperative stroke, and development of renal failure or acute respiratory distress syndrome, but not reoperative status, as predictors of mortality.

CONCLUSIONS

The risk of AVR after previous CABG is similar to that for primary AVR+CABG. Valve replacement should, therefore, be pursued despite prior CABG when hemodynamically significant aortic stenosis develops. Furthermore, a circumspect approach to "prophylactic" AVR for mild aortic stenosis at primary CABG seems warranted.