Etiology of aortic valve disease and recent changes in Japan:a study of 600 valve replacement cases

Patients with a Bicuspid Aortic Valve (BAV) Diagnosed with ECG-Gated Cardiac Multislice Computed Tomography-Analysis of the Reasons for Referral, Classification of Morphological Phenotypes, Co-Occurring Cardiovascular Abnormalities, and Coronary Artery Stenosis

Background/Objectives: The aim of this study was to analyze a group of patients with a bicuspid aortic valve (BAV) examined with ECG-gated cardiac CT (ECG-CT), focusing on the assessment of the clinical reasons for cardiac CT, cardiovascular abnormalities coexisting with their BAV, and coronary artery stenosis. Methods: A detailed statistical analysis was conducted on 700 patients with a BAV from a group of 15,670 patients examined with ECG-CT. Results: The incidence of a BAV in ECG-CT was 4.6%. The most common reason for examination was suspicion of coronary heart disease-31.1%. Cardiovascular defects most frequently associated with a BAV were a VSD (4.3%) and coarctation of the aorta (3.6%), while among coronary anomalies, they were high-take-off coronary arteries (6.4%) and paracommissural orifice of coronary arteries (4.4%). The analysis of the coronary artery calcium index showed significantly lower values for type 2 BAV compared to other valve types (p < 0.001), with the lowest average age in this group of patients. Moreover, the presence of a raphe between the coronary and non-coronary cusps was associated with a higher rate of significant coronary stenosis compared to other types of BAVs (p < 0.001). Conclusions: The most common reason for referral for cardiac ECG-CT in the group ≤ 40-year-olds with a BAV was the suspicion of congenital cardiovascular defects, while in the group of over 40-year-olds, it was the suspicion of coronary artery disease. The incidence of cardiovascular abnormalities co-occurring with BAV and diagnosed with ECG-CT differs among specific patient subgroups. The presence of a raphe between the coronary and non-coronary cusps appears to be a potential risk factor for significant coronary stenosis in patients with BAVs.

Clinical impact of pathology-proven etiology of severely stenotic aortic valves on mid-term outcomes in patients undergoing surgical aortic valve replacement

Background

The use of transcatheter or surgical aortic valve replacement (AVR) for severe aortic stenosis (AS) has considerably increased in recent years. However, the association between AS etiology and mid-term clinical outcomes after surgical AVR has not been fully investigated.

Methods and results

We retrospectively included 201 patients (mean age, 75 years; 43%, men) who underwent surgical AVR for severe native AS (aortic valve area ≤1.0 cm² on preoperative transthoracic echocardiography examination). The following valve etiologies were postoperatively identified on pathological examination: post-inflammatory (n = 28), congenital (n = 35), and calcific/degenerative (n = 138). The median follow-up interval was 4.1 years following surgical AVR. Of the 201 patients, 27% were asymptomatic, 40% had a history of heart failure, and 11% underwent previous heart surgery. The cumulative incidence of cardiac events (all-cause death, aortic valve deterioration requiring repeated AVR, and hospitalization for heart failure) and combined adverse events, which included non-fatal stroke, unplanned coronary revascularization, pacemaker implantation, and gastrointestinal bleeding along with cardiac events, was significantly higher in the calcific/degenerative group (p = 0.02 and p = 0.02, respectively). In multivariate analysis adjusted for age, sex, renal function, heart failure, atrial fibrillation, concomitant surgical procedures, and EuroSCORE II, AS etiology was independently associated with an increased risk of combined adverse events (congenital vs. post-inflammatory: hazard ratio [HR], 4.13; p = 0.02 and calcific/degenerative vs. post-inflammatory: HR, 5.69; p = 0.002).

Conclusions

Pathology-proven AS etiology could aid in predicting the mid-term outcomes after surgical AVR, supporting the importance of accurate identification of severe AS etiology with or without postoperative pathological examination.

Propensity score-matched analysis of patients with severe aortic stenosis undergoing surgical aortic valve replacement

Objective

Severe aortic stenosis (AS) is one of the most serious valve conditions. Patient demography and the aetiology of AS have substantially changed in the past several decades along with a drastic improvement of surgical aortic valve replacement (SAVR) and its associated procedures. Contemporary patients with severe AS have multiple comorbidities and live much longer. We aimed to elucidate the treatment effects of SAVR on long-term outcome in propensity score (PS)-matched and the entire patient populations.

Methods

We retrospectively reviewed 570 patients with severe AS defined as an aortic valve area of 1.0 cm² or less. Systemic differences in 39 baseline characteristics between non-SAVR and SAVR groups were adjusted using PS matching method. The endpoints included all-cause mortality and cardiovascular events that included heart failure, non-fatal stroke, syncope and acute coronary syndrome.

Results

Overall, 55% of the entire population (mean age 78 years; males 41%) were symptomatic. During 3.9 years of the median follow-up, 210 (36%) patients underwent SAVR and 231 (41%) died. Cumulative incidences of mortality and both mortality and cardiovascular events were significantly higher in the non-SAVR group than in the other group (p<0.001, each). Among 101 PS-matched pairs, SAVR correlated with a lower mortality risk (HR 0.35; 95% CI 0.21 to 0.59; p<0.001)) and mortality and cardiovascular events combined (HR 0.62; 95% CI 0.42 to 0.92; p=0.02). However, survival difference between both groups was markedly smaller among asymptomatic patients in the subgroup of matched patients.

Conclusion

Patients with AS undergoing SAVR exhibit a lower incidence of all-cause mortality and major cardiovascular events than those not undergoing surgical interventions, even after the baseline characteristics are balanced by the PS matching. The correlation between SAVR and survival from cardiovascular events is less evident among asymptomatic patients.

Transcatheter aortic valve replacement in patients with degenerative calcified rheumatic aortic stenosis: A 10-patient case series

BACKGROUND

Transcatheter aortic valve replacement (TAVR) for patients with rheumatic heart disease (RHD) has not been well-known. This study aimed to assess characteristics and computed tomography (CT) findings of the aortic valve in old patients with RHD and to investigate the safety and efficacy in the patients who underwent TAVR.

METHODS AND RESULTS

Of 352 consecutive patients with severe aortic stenosis (AS) who underwent TAVR at the Sakakibara Heart Institute between 2013 and 2016, 10 patients (2.8%) were considered to have degenerative calcified rheumatic AS by transthoracic echocardiography. Young patients with rheumatic AS without any calcification were not indicated for TAVR in this study. They were likely to have previous pacemaker implantation, atrial fibrillation, anticoagulants, diuretics, reduced ejection fraction, mitral valve involvement, and high pulmonary artery pressure. CT was able to clearly visualize irregular valve thickening, commissure fusion, and a relatively small amount of calcification from the tip of the leaflet to the base of the aortic valve. Mortality at 30 days after TAVR was 0%, with a mean Society of Thoracic Surgeons Score of 7 ± 4%. Device success was 90%, and no patients met the safety endpoint at 30 days.

CONCLUSIONS

CT was able to visualize the calcified aortic valve in old patients with RHD, and we demonstrate the safety and efficacy of TAVR in this specific population. Care should be taken for procedural success in particular characteristics with marginal calcified aortic valve, anticoagulant use with low body mass index, or concomitant mitral valve disease.

Matrix Gla protein negatively regulates calcification of human aortic valve interstitial cells isolated from calcified aortic valves

Calcified aortic valve stenosis (CAS) is a common heart valve disease in elderly people, and is mostly accompanied by ectopic valve calcification. We recently demonstrated that tumor necrosis factor-α (TNF-α) induces calcification of human aortic valve interstitial cells (HAVICs) obtained from CAS patients. In this study, we investigated the role of matrix Gla protein (MGP), a known calcification inhibitor that antagonizes bone morphogenetic protein 2 (BMP2) in TNF-α-induced calcification of HAVICs. HAVICs isolated from aortic valves were cultured, and calcification was significantly induced with 30 ng/mL TNF-α. Gene expression of the calcigenic marker, BMP2, was significantly increased in response to TNF-α, while the gene and protein expression of MGP was strongly decreased. To confirm the role of MGP, MGP-knockdown HAVICs and HAVICs overexpressing MGP were generated. In HAVICs, in which MGP expression was inhibited by small interfering RNA, calcification and BMP2 gene expression were induced following long-term culture for 32 days in the absence of TNF-α. In contrast, HAVICs overexpressing MGP had significantly decreased TNF-α-induced calcification. These results suggest that MGP acts as a negative regulator of HAVIC calcification, and as such, may be helpful in the development of new therapies for ectopic calcification of the aortic valve.

A Preoperative Assessment of Significant Coronary Stenosis Based on a Semiquantitative Analysis of Coronary Artery Calcification on Noncontrast Computed Tomography in Aortic Stenosis Patients Undergoing Aortic Valve Replacement

Invasive coronary angiography (ICA) is the recommended assessment for coronary artery disease in patients undergoing elective aortic valve replacement (AVR). Noncontrast computed tomography (CT) is useful for evaluating lung lesions and calcifications at the cannulation site of the ascending aorta. The purpose of this study was to evaluate the role of noncontrast CT in the visual assessment of coronary artery calcification (CAC) in patients undergoing AVR. We retrospectively identified patients with significant aortic stenosis (AS) who were referred for AVR between January 2006 and December 2013. Among these, we included 386 patients (53.6% males, 69.2 ± 8.4 years) who underwent both noncontrast CT and ICA. Significant coronary artery stenosis (CAS) in the ICA was defined as luminal stenosis ≥70%. The 4 main coronary arteries were visually assessed on noncontrast CT and were scored based on the Weston score as follows: 0, no visually detected calcium; 1, a single high-density pixel detected; 3, calcium was dense enough to create a blooming artifact; and 2, calcium in between 1 and 3. Four groups were reclassified by the sum of the Weston scores from each vessel, as follows: noncalcification (0); mild calcification (1-4); moderate calcification (5-8); and severe calcification (9-12). Receiver-operating characteristic (ROC) analysis was generated to identify the cutoff Weston score values for predicting significant CAS. Diagnostic estimates were calculated based on these cutoffs. In the ICA analysis, 62 of the 386 patients (16.1%) had significant CAS. All patients were divided into 4 groups. The noncalcification group had 97 subjects (Weston score 0), the mild degree group had 100 (2.6 ± 1.0), the moderate calcification group had 114 (6.6 ± 1.1), and the severe calcification group had 75 (10.7 ± 1.1). The prevalence of significant CAS in the noncalcification, mild, moderate, and severe groups was 1% (1/97), 5% (5/100), 24% (27/114), and 39% (29/75), respectively. The group with CAS had significantly more CAC than the group without CAS (8.37 ± 2.93 vs 4.01 ± 3.75, P < 0.001). The cutoff value (by Weston score) for predicting significant CAS is ≥5 (sensitivity 90.3%, specificity 59.0%, positive predictive value 29.6%, and negative predictive value 97%). The degree of CAC detected on noncontrast CT can help to predict significant CAS in AS patients who are referred for AVR. For the clinicians, the visual assessment of CAC on noncontrast CT was easy and useful for estimating CAS. Therefore, ICA should be recommended to selective patients based on patients' CAC and Weston scores during the preoperative evaluation for elective AVR.

Causes of death and mortality and evaluation of prognostic factors in patients with severe aortic stenosis in an aging society

BACKGROUND

Severe aortic stenosis (AS) is now predominantly a disease of the elderly, with significant mortality and morbidity. In order to investigate the burden of severe AS in the current population, we assessed mortality, causes of death, clinical event rates, and prognostic factors of patients diagnosed with severe AS.

METHODS

A total of 519 consecutive patients (mean age, 78±9 years) with severe AS (aortic valve area <1.0 cm(2)) were retrospectively analyzed. All-cause mortality and clinical events including aortic valve replacement, heart failure requiring admission, acute coronary syndrome, and syncope were measured as main outcome.

RESULTS

During a median follow-up of 3.5 years, 167 patients (32%) died. Overall survival rates at 1 and 3 years were 86% and 70%, respectively. Of all deaths, 101 (61%) were cardiovascular-related and 56 (33%) were non-cardiovascular. Syncope occurred in only 18 (4%) patients, while heart failure requiring admission occurred in 188 (43%) patients as the most frequent event. Male, severe symptoms (New York Heart Association functional class, III/IV), inactive state, previous history of heart failure, renal insufficiency, hemodialysis treatment, peripheral vascular disease, malignancy, and statin use at enrollment were significantly and independently associated with death among the patients.

CONCLUSIONS

Among the one-third of severe AS patients who died during follow-up, 61% of deaths were cardiovascular-related. Cardiovascular death may be the leading, but not the only, cause of death for contemporary severe AS patients. Factors such as severe symptomatic status, lower daily activity level, and chronic kidney diseases were strong predictive factors of worse survival in this population.

The bicuspid aortic valve and related disorders

Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation, affecting 1-2% of the population, with strong male predominance. Individuals may have a normally functioning BAV, and may be unaware of its presence and the potential risk of complications. However, they may easily develop aortic valve disorders: either stenotic or regurgitant, or both. Today, BAV is recognized as a syndrome incorporating aortic valve disorders and aortic wall abnormalities, including aortic dilation, dissection or rupture. Congenital or hereditary diseases such as ventricular septal defect, patent ductus arteriosus, coarctation of the aorta, Turner's syndrome, Marfan's syndrome etc., may frequently be associated with BAV. Infective endocarditis and occasionally thrombus formation may develop during the lives of BAV patients. Elevated cholesterol or C-reactive protein may be seen in laboratory findings of these patients. Beta-blockers and statins are the possibilities for medical treatment, and aortic valve repair/replacement and ascending aorta replacement are indicated for patients with a severely diseased aortic valve and aorta. Rigorous follow-up throughout life is mandatory after BAV has been diagnosed. The aim of the present article was to describe the implications of BAV and its associated disorders, and to discuss diagnostic and treatment strategies.

Implications of a congenitally abnormal valve: a study of 1025 consecutively excised aortic valves

Background:

An increasing proportion of patients with congenitally abnormal aortic valves (AV) present for AV replacement.

Aims:

To review morphological changes in a large contemporary patient population undergoing AV replacement.

Methods:

A detailed review was conducted for all 1025 patients who underwent AV replacement from 2002 to 2005, including the clinical indication for surgery, the type of native AV disease, the pathological changes observed in each valve and the need for related surgery.

Results:

Tricuspid (TAV), bicuspid (BAV) and unicuspid (UAV) aortic valves were observed in 64.5%, 31.9% and 3.0% of all patients respectively. A decreased number of cusps was associated with increasing predilection for male gender (83.9%, 73.4%, 59.2% for UAV, BAV, TAV respectively), a younger patient age at surgery (41.6 (14.3), 61.3 (12.8), 67.5 (12.9) years), and an increased occurrence of pathological changes in the cusps, including calcification of both the cusp and the base, ossification and ulceration. UAV and BAV were also associated with increasing replacement of the ascending aorta due to dilatation and aneurysm formation (54.8, 38.8%, 16.6%). The incidence of infective endocarditis and rheumatic heart disease was 3.8% and 11.2% of all excised valves respectively.

Conclusion:

UAV and BAV were increasingly likely to affect men, fail at an earlier age, and show an increasing incidence of pathological changes in the cusps and ascending aorta than TAV. These results suggest that TAV, BAV and UAV may represent a phenotypic continuum of a similar disease process.