Clinical significance and prognostic value of ST segment depression on ECG during exercise treadmill test in asymptomatic patients with moderate or severe aortic stenosis.

Objectives. In patients with asymptomatic moderate or severe aortic stenosis (AS), exercise testing is used for evaluating the need for aortic valve intervention. Expert opinions about the clinical significance and prognostic value of ST segment depression on electrocardiography (ECG) during exercise testing in AS is conflicting and there are no large studies exploring this issue. We aimed to explore the association of ST segment depression >5 mm during exercise treadmill test (ETT) with all-cause mortality, aortic valve replacement (AVR) or cardiac-related hospitalization. Design. We performed a retrospective analysis of prospectively collected data of a total of 315 patients (mean age 65 ± 12 years, 67% men) with asymptomatic moderate (n = 209; 66%) or severe (n = 106; 34%) AS. All patients underwent clinical evaluation, echocardiography and ETT. Results. During a mean follow-up of 34.9 ± 34.6 months, 29 (9%) patients died and 235 (74%) underwent AVR. The prevalence of ST segment depression (>5 mm) was 13% (n = 41) in the total study population and was comparable in patients with revealed symptoms (17.6%, n = 16) versus without revealed symptoms (11.3%, n = 25; p = .132). ST segment depression on ETT was strongly associated with aortic valve area. In univariate Cox regression analysis, ST segment depression was not associated with cardiac related hospitalizations (HR 1.65; 95% CI 0.89-3.10, p = .113), all-cause mortality (HR 1.37; 95% CI 0.47-3.98, p = .564) or AVR (HR 1.30; 95% CI 0.89-1.91, p = .170). Conclusion. In patients with moderate or severe AS, ST segment depression during ETT is non-specific, carries no prognostic risk and should be used with caution in the clinical interpretation of exercise test.

Left atrial volume index predicts adverse events in asymptomatic moderate or severe aortic stenosis.

OBJECTIVE: In aortic stenosis (AS), chronic pressure overload on left ventricle (LV) leads to LV hypertrophy, impaired relaxation, increased chamber stiffness, fibrosis and left atrial (LA) dilatation. An enlarged LA may be a marker of longstanding diastolic dysfunction (DD) and more advanced disease in AS. We aimed to assess the impact of LA volume index (LAVI) on events in patients with moderate or severe AS. METHODS: A total of 324 patients (mean age 69 ± 13 years, 61% men) were included. LA volume was measured by biplane Simpson's method using apical four- and two-chamber views and indexed to body surface area. An increased LAVI was defined as > 34 ml/m2 . RESULTS: The mean EF was 64 ± 8%, LAVI 35 ± 14 ml/m2 and flow rate 244 ± 70 ml/s. The number of total events was 275 (85%): 243 (75%) aortic valve replacement and 32 (10%) deaths. Mean follow-up 23.7 ± 23.8 months (median 15.2 months). An increased LAVI (45% [n = 145]) was associated with adverse events (HR 1.86; 95% CI 1.24-2.82, p = 0.003) independent of age, smoking, diabetes, atrial fibrillation, LV ejection fraction, LV mass, aortic valve area, and low flow rate (<200 ml/s). In the same multivariate model, when increased LAVI was replaced by E/e' ratio ≥14 cm, no association was found between E/e' ratio ≥14 cm and adverse events (HR 1.18; 95% CI .78-1.78, p = 0.430). CONCLUSION: LAVI was an independent predictor of adverse events in patients with moderate or severe AS and preserved ejection fraction. Including LAVI in the risk assessment of AS patients may further improve risk stratification.

The case for a specialist multidisciplinary valve clinic.

Valve disease is common and is increasing in prevalence as the population ages. The delivery of appropriate management is not always straightforward, and better ways of organizing care are required. Here, the argument is made for a specialist multidisciplinary valve clinic, while a description is provided of the authors' model clinic, which incorporates a specialist cardiologist in addition to sonographers and a nurse who carry out the surveillance services. The clinic is based at a cardiothoracic center and one district hospital, but could be generalized. Previous audits have shown that this model can reduce the number of patients seen by a cardiologist, thus improving the safety and quality of treatment compared to conventional clinics.

The CryoLife-O'Brien stentless replacement aortic valve: patterns of valve failure.

BACKGROUND AND AIM OF THE STUDY: The study aim was to describe patterns of failure in a consecutive series of patients with the CryoLife-O'Brien stentless porcine aortic bioprosthesis. METHODS: The records of patients requiring redo surgery were reviewed. All surviving patients were contacted and questioned about clinical events since implantation of the valve. RESULTS: The early mortality was 7%, whilst 4% of patients died between 30 days and one year after surgery, and 31% died beyond one year. Six cases of structural deterioration were identified; five of these cases were due to a cusp tear (usually of the right coronary cusp), and one case was due to valve calcification. There were five cases of non-structural dysfunction; dehiscence was present in three of these cases, with progression of minor periprosthetic regurgitation seen immediately after surgery. Three failures occurred as a result of infective endocarditis. Structural valve deterioration or dehiscence occurred at a mean of 52 months after surgery, with no step-up in incidence at any time-point. Primary failure occurred in three of 49 (6%) bioprostheses manufactured after June 2003, and in eight of 117 (7%) manufactured before June 2003. CONCLUSION: The incidence of primary valve failure at 52 months after implantation was found to be 7%. It is suggested that routine echocardiography be performed at least annually, particularly in those patients with even minor paraprosthetic regurgitation on the postoperative study.

Sex-differences in aortic stenosis: Effect on functional capacity and prognosis.

BACKGROUND: The patterns of left ventricular (LV) remodeling in aortic stenosis (AS) are different in men and women. We aimed to assess whether there were also sex differences in measurements obtained on exercise testing. METHODS: Echocardiography and ETT (modified Bruce) were performed at presentation in 316 patients with moderate or severe AS. An early rapid rise in heart rate (RR-HR) during ETT was defined as achieving at least 85% of target heart rate or ≥50% increase from baseline within the first 6 min. RESULTS: Mean age was 66 ± 12 years in men (n = 212) and 65 ± 12 years in women (n = 104) (p = NS). Men walked longer than women on the treadmill (10.4 ± 4.3 vs. 8.2 ± 4.2 min, p < 0.001) and achieved higher METs (9.2 ± 4.5 vs. 7.6 ± 4.3, p < 0.001), but both sexes achieved similar levels of peak heart rate and blood pressure. During a mean follow up of 34.9 ± 34.6 months, 29 deaths occurred (20 in men and 9 in women, p = 0.821). Age and body mass index were strong determinants of lower METs in men, but not in women, while Zva was a determinant in women but not in men. RR-HR was a strong determinant of lower METs in both sexes. Event-free survival was significantly lower in men with RR-HR but not in women. CONCLUSION: Exercise capacity was lower in women than men, and the determinants of exercise capacity differed. An RR-HR was a strong determinant of lower METs in both sexes, but predicted all-cause mortality only in men.

Antihypertensive treatment with calcium channel blockers in patients with moderate or severe aortic stenosis: Relationship with all-cause mortality.

BACKGROUND: Hypertension is common in patients with aortic stenosis (AS) and optimal blood pressure (BP) control is advised to reduce arterial load and cardiovascular events. Whether calcium channel blockers (CCB) are safe is not known. METHODS: This was a retrospective analysis of 314 patients (age 65 ±â€¯12 years, 68% men) with moderate or severe asymptomatic AS. Hypertension was defined from a history of hypertension, past or current antihypertensive treatment or a BP at the baseline clinic visit >140/90 mmHg. All patients underwent an exercise treadmill test (ETT) and echocardiography. RESULTS: The prevalence of hypertension was 73.6%, and 65% took antihypertensive treatment. Patients who used a CCB (25%) (CCB+) were older, more likely to have hypercholesterolemia and coronary artery disease, and had higher systolic BP, stroke work, left ventricular mass compared to CCB-patients (all p < 0.05). During the baseline ETT, CCB+ patients achieved a lower peak heart rate, a shorter exercise time and were more likely to have a blunted BP response compared to CCB- patients (p < 0.05). Event-free survival was significantly lower in CCB+ than CCB- patients (all-cause mortality 16 [20.3%] versus 13 [5.6%]; p < 0.001). In a multivariable Cox regression model, CCB+ was associated with a 7-fold increased hazard ratio (HR) for all-cause mortality (HR 7.09; 95% CI 2.15-23.38, p = 0.001), independent of age, hypertension, diabetes, left ventricular ejection fraction, and aortic valve area. CONCLUSION: The use of CCB was associated with an adverse effect on treadmill exercise and reduced survival in asymptomatic patients with moderate or severe AS.

Specialist valve clinic in a cardiac centre: 10-year experience.

Aims: Guidelines recommend specialist valve clinics as best practice for the assessment and conservative management of patients with heart valve disease. However, there is little guidance on how to set up and organise a clinic. The aim of this study is to describe a clinic run by a multidisciplinary team consisting of cardiologists, physiologist/scientists and a nurse. Methods: The clinical and organisational aims of the clinic, inclusion and exclusion criteria, and links with other services are described. The methods of training non-clinical staff are detailed. Data were prospectively entered onto a database and the study consisted of an analysis of the clinical characteristics and outcomes of all patients seen between 1 January 2009 and 31 December 2018. Results: There were 2126 new patients and 9522 visits in the 10-year period. The mean age was 64.8 and 55% were male. Of the visits, 3587 (38%) were to the cardiologists, 4092 (43%) to the physiologist/scientists and 1843 (19%) to the nurse. The outcomes from the cardiologist clinics were cardiology follow-up in 460 (30%), referral for surgery in 354 (23%), referral to the physiologist/scientist clinic in 412 (27%) or to the nurse clinic in 65 (4.3%) and discharge in 230 (15%). The cardiologist needed to see 6% from the nurse clinic and 10% from the physiologist/scientist clinic, while advice alone was sufficient in 10% and 9%. Conclusion: A multidisciplinary specialist valve clinic is feasible and sustainable in the long term.

EDUCATIONAL SERIES ON THE SPECIALIST VALVE CLINIC: What is a valve clinic?

The prevalence of heart valve disease is increasing as the population ages. A series of studies have shown current clinical practice is sub-optimal. Some patients are referred for surgery at advanced stages of disease with impaired ventricular function or not even considered for surgery. Valve clinics seek to improve patient outcomes by providing an expert-led, patient-centred framework of care designed to provide an accurate diagnosis with active surveillance of valve pathology and timely referral for intervention at guideline directed trigger points. A range of different valve clinic models can be adopted depending on local expertise combining the skill set of cardiologist, physiologist/scientist and nurses. Essential components to all clinics include structured clinical review, echocardiography to identify disease aetiology and severity, patient education and access to both additional diagnostic testing and a multi-disciplinary meeting for complex case review. Recommendations for training in heart valve disease are being developed. There is a growing evidence base for heart valve clinics providing better care with increased adherence to guideline recommendations, more timely referral for surgery and better patient education than conventional care.

Rapid early rise in heart rate on treadmill exercise in patients with asymptomatic moderate or severe aortic stenosis: a new prognostic marker?

Objective: To examine the clinical significance and prognostic value of an early rapid rise in heart rate (RR-HR) in asymptomatic patients with moderate or severe aortic stenosis (AS). Methods: We retrospectively assessed the prospectively collected data from 306 patients (age 65±12 years, 33% women) with moderate (n=204) or severe AS (n=102) with a median follow-up of 25 months (mean 34.9±34.6 months). All had echocardiography and modified Bruce exercise treadmill tests (ETT). RR-HR was defined as achieving 85% target HR or ≥50% increase from baseline in the first 6 min. The outcome measures were revealed symptoms during ETT, aortic valve replacement (AVR) and all-cause mortality. Results: RR-HR occurred in 77 (25%) and 64% developed revealed symptoms (postive predictive value 64% and negative predictive value 84%). On univariate Cox regression analyses in patients with severe AS, RR-HR was associated with AVR (HR 3.32, 95% CI 2.03 to 5.45, p<0.001) but not with all-cause mortality (HR 0.04, 95% CI 0.13 to 9.21, p=0.798). In patients with moderate AS, RR-HR was associated with all-cause mortality (HR 2.67, 95% CI 1.09 to 6.56, p=0.032), but not with AVR (HR 1.35, 95% CI 0.92 to 1.98, p=0.127). These associations remained significant in multivariate Cox regression analyses after adjustment for age, sex, hypertension, coronary artery disease, abnormal blood pressure response, Doppler stroke volume and mean pressure gradient (both p<0.001). Conclusions: RR-HR was associated with the development of revealed symptoms. It predicted revealed symptoms on serial ETT, AVR in severe AS and all-cause mortality in moderate AS. RR-HR may be a useful new measure to define risk in AS.

Hypertension in aortic stenosis: relationship with revealed symptoms and functional measures on treadmill exercise.

BACKGROUND: The impact of hypertension on symptoms and functional capacity during exercise treadmill test (ETT) in apparently asymptomatic patients with aortic stenosis is poorly understood. METHODS: A total of 314 patients (age 65 ±â€Š12 years, 68% men) with moderate or severe asymptomatic aortic stenosis underwent baseline echocardiography and ETT. Hypertension was defined as a history of elevated blood pressure (BP), past or current treatment with antihypertensive agents or a BP at the baseline clinic visit more than 140/90 mmHg. RESULTS: There were 229 (73%) patients with hypertension who were older, more likely to have diabetes, hypercholesterolemia and coronary artery disease, larger left atrial diameters, higher left ventricular (LV) mass and a higher proportion of LV hypertrophy than normotensive patients. In a univariate logistic regression analysis hypertension and clinic SBP were not associated with revealed symptoms. In a multivariate logistic regression analysis, lower peak SBP [odds ratio (OR) 1.02;95% confidence interval (CI) 1.00-1.04, P = 0.017] and rapid early rise in heart rate (OR 15.03; 95% CI 6.23-36.24, P < 0.001) were associated with a higher risk of revealed symptoms while the use of antihypertensive treatment was associated with a lower risk of revealed symptoms (OR 0.40; 95% CI 0.18-0.89, P = 0.025), independent of age, obesity, LV ejection fraction and aortic valve area. In a linear regression analysis, after adjustment for age, sex and BMI, hypertension did not retain an association with lower metabolic equivalents (ß = -0.06, P = 0.311). CONCLUSION: Hypertension in aortic stenosis patients was associated with a high cardiovascular disease burden, but did not interact with symptoms or functional capacity during ETT. Hypertension does not interfere with the clinical interpretation of exercise testing.

Exercise testing in patients with asymptomatic moderate or severe aortic stenosis.

OBJECTIVE: To assess the safety and tolerability of treadmill exercise testing and the association of revealed symptoms with outcome in apparently asymptomatic patients with moderate to severe aortic stenosis (AS). METHODS: A retrospective cohort study of 316 patients (age 65±12 years, 67% men) with moderate and severe AS who underwent echocardiography and modified Bruce exercise treadmill tests (ETTs) at a specialist valve clinic. The outcome measures were aortic valve replacement (AVR), all-cause mortality or a composite of AVR and all-cause mortality. RESULTS: At baseline, there were 210 (66%) patients with moderate and 106 (34%) with severe AS. There were 264 (83%) events. 234 (74%) patients reached an indication for AVR, 145 (69%) with moderate and 88 (83%) with severe AS (p<0.05). Of the 30 (9%) deaths recoded during follow-up, 20 (67%) were cardiovascular related. In total, 797 exercise tests (mean 2.5±2.1 per patient) were performed. No serious adverse events were observed. The prevalence of revealed symptoms at baseline ETT was 29% (n=91) and was significantly higher in severe AS compared with moderate AS (38%vs23%, p=0.008). Symptoms were revealed in 18%-59% of patients during serial ETT conducted over a follow-up period of 34.9 (SD 35.1) months. The event-free survival at 24 months with revealed symptoms was 46%±4% and without revealed symptoms was 70%±4%. CONCLUSIONS: ETT in patients with moderate or severe AS is safe and tolerable. Serial exercise testing is useful to reveal symptoms not volunteered on the history and adds incremental prognostic information to baseline testing.

A comparison of early redo surgery rates in Mosaic porcine and Perimount bovine pericardial valves.

OBJECTIVES: The objective of this study was to compare rates of redo surgery for the Medtronic Mosaic 305 A Porcine Prosthesis and the Carpentier-Edwards Perimount Pericardial Aortic Bioprosthesis 2900. METHODS: This was a single-centre retrospective observational study. We included all 1018 patients who underwent aortic valve replacement with a Mosaic (n = 216) or Perimount (n = 809) bioprosthesis between October 2000 and August 2008. The total follow-up was 1508 patient-years for the Mosaic valve and 5813 for the Perimount valve. The maximal follow-up and interquartile range were 14.8 and 7.0 years for the Mosaic valve and 15.1 and 5.6 years for the Perimount valve, respectively. A propensity score-weighted version of the Cox model, Kaplan-Meier analysis and multivariate regression model was used. RESULTS: Despite no statistical difference in the number of non-structural valve deterioration cases between valves, redo surgery occurred earlier in 10 (4.6%) Mosaic than for 17 (2.1%) Perimount valves (P = 0.02) and was required for structural valve deterioration in 5 (2.3%) Mosaic valves when compared with 7 (0.9%; P = 0.04) Perimount valves. Four of 5 Mosaic failures occurred before 5 years, whereas all Perimount failures occurred after 5 years. Redo surgery for non-structural valve deterioration occurred in 3 patients with Mosaic valves (1.4%) and no patients with Perimount valves. Surgery for the remaining patients with Perimount valves was due to infection or aortic disease. CONCLUSIONS: Early redo surgery for structural valve degeneration was uncommon but occurred earlier for the Mosaic porcine than the Perimount bovine pericardial replacement aortic valve.

Exercise Treadmill Testing in Moderate or Severe Aortic Stenosis: The Left Ventricular Correlates of an Exaggerated Blood Pressure Rise.

Background Exaggerated blood pressure response during exercise predicts future hypertension and cardiovascular events in general population and different patients groups. However, its clinical and prognostic implications in patients with aortic stenosis have not been previously evaluated. Methods and Results We retrospectively studied 301 patients with moderate to severe asymptomatic aortic stenosis (aged 65±12 years) who underwent echocardiography and a modified Bruce exercise treadmill test. An exaggerated blood pressure response was defined as peak systolic blood pressure ≥190 mm Hg. An abnormal blood pressure response (either blunted or exaggerated) was found in 58% of patients and abnormal left ventricular geometry in 82%. There was no difference in the rates of abnormal blood pressure responses between patients with moderate and severe aortic stenosis ([exaggerated blood pressure response: 21% versus 22%, P=0.876] and [blunted blood pressure response: 35% versus 40%, P=0.647]). Patients with exaggerated blood pressure response (21%) were more likely to be older, have hypertension, higher pretest systolic blood pressure, left ventricular ejection fraction and mass, and increased arterial stiffness (all P<0.05). In a multivariate logistic regression analysis, an exaggerated blood pressure response was associated with higher pulse pressure/stroke volume index (odds ratio 2.45, 95% confidence interval 1.02-6.00, P=0.037) and left ventricular mass (odds ratio 2.04, 95% confidence interval 1.23-3.38, P=0.012) independent of age, hypertension, aortic annulus and left atrium diameter, and left ventricular ejection fraction. Conclusions In those with aortic stenosis, exaggerated blood pressure was strongly related to higher resting blood pressure values, left ventricular mass, and increased arterial stiffness independent of hypertension.

A comparison of two forms of the continuity equation in the Trifecta bovine pericardial aortic valve.

AIM: To compare the classical and simplified form of the continuity equation in small Trifecta valves. METHODS: This is a retrospective analysis of post-operative echocardiograms performed for clinical reasons after implantation of Trifecta bioprosthetic valves. RESULTS: There were 60 patients aged 74 (range 38-89) years. For the valves of size 19, 21 and 23mm, the mean gradient was 11.3, 10.7 and 9.7mmHg, respectively. The effective orifice areas by the classical form of the continuity equation were 1.4, 1.7 and 1.9cm(2), respectively. There was a good correlation between the two forms of the continuity equation, but they were significantly different using a t-test (P<0.00001). Results using the classical form were a mean 0.11 (s.d. 0.18)cm(2) larger than those using the simple formula. CONCLUSION: Haemodynamic function of the Trifecta valve in the small aortic root is good. There are significant differences between the classical and simplified forms of the continuity equation.

Bovine pericardial versus porcine stented replacement aortic valves: early results of a randomized comparison of the Perimount and the Mosaic valves.

OBJECTIVE: A stented bovine pericardial valve might be less obstructive than a stented porcine valve. This study compared early hemodynamic function in a prospective series of 99 patients randomized to receive either a Mosaic or Perimount replacement aortic valve. METHODS: Echocardiography was performed early after surgery and at 1 year after surgery. Patients also filled in psychologic questionnaires and underwent a 6-minute walk. RESULTS: The groups were matched demographically. The Perimount valve was significantly less obstructive in terms of mean pressure difference (11 +/- 5 vs 17 +/- 7 mm Hg; P < .0001), with a trend in favor of a larger effective orifice area (1.47 +/- 0.45 vs 1.28 +/- 0.46 cm(2); P = .05) postoperatively. There were no differences in left ventricular mass regression, aortic regurgitation, 6-minute walk, psychologic questionnaires, or mortality and clinical events. CONCLUSION: The stented bovine pericardial valve was less obstructive than the stented porcine valve. Both valves were associated with similar and significant improvements in quality of life, exercise ability, and regression of left ventricular mass.