Magnetic Resonance Left Ventricle Mass-Index/Fibrosis: Long-Term Predictors for Ventricular Arrhythmia in Hypertrophic Cardiomyopathy-A Retrospective Registry.

Objective: We aimed to study the long-term association of LV mass index (LVMI) and myocardial fibrosis with ventricular arrhythmia (VA) in a population of patients with confirmed hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance imaging (CMR). Methods: We retrospectively analyzed the data in consecutive HCM patients confirmed on CMR referred to an HCM clinic between January 2008 and October 2018. Patients were followed up yearly following diagnosis. Baseline demographics, risk factors and clinical outcomes from cardiac monitoring and an implanted cardioverter defibrillator (ICD) were analyzed for association of LVMI and LV late gadolinium enhancement (LVLGE) with VA. Patients were then allocated to one of two groups according to the presence of VA (Group A) or absence of VA (Group B) during the follow-up period. The transthoracic echocardiogram (TTE) and CMR parameters were compared between the two groups. Results: A total of 247 patients with confirmed HCM (age 56.2 ± 16.6, male = 71%) were studied over the follow-up period of 7 ± 3.3 years (95% CI = 6.6-7.4 years). LVMI derived from CMR was higher in Group A (91.1 ± 28.1 g/m2 vs. 78.8 ± 28.3 g/m2, p = 0.003) when compared to Group B. LVLGE was higher in Group A (7.3 ± 6.3% vs. 4.7 ± 4.3%, p = 0.001) when compared to Group B. Multivariable Cox regression analysis showed LVMI (hazard ratio (HR) = 1.02, 95% CI = 1.001-1.03, p = 0.03) and LVLGE (HR = 1.04, 95% CI = 1.001-1.08, p = 0.04) to be independent predictors for VA. Receiver operative curves showed higher LVMI and LVLGE with a cut-off of 85 g/m2 and 6%, respectively, to be associated with VA. Conclusions: LVMI and LVLGE are strongly associated with VA over long-term follow-up. LVMI requires more thorough studies to consider it as a risk stratification tool in patients with HCM.

Silent cerebral infarction and cognitive function following TAVI: an observational two-centre UK comparison of the first-generation CoreValve and second-generation Lotus valve.

OBJECTIVE: To compare the incidence of silent cerebral infarction and impact on cognitive function following transcatheter aortic valve implantation (TAVI) with the first-generation CoreValve (Medtronic, Minneapolis, Minnesota, USA) and second-generation Lotus valve (Boston Scientific, Natick Massachusetts, USA). DESIGN: A prospective observational study comprising a 1.5 T cerebral MRI scan, performed preoperatively and immediately following TAVI, and neurocognitive assessments performed at baseline, 30 days and 1 year follow-up. SETTING: University hospitals of Leeds and Leicester, UK. PATIENTS: 66 (80.6±8.0 years, 47% male) patients with high-risk severe symptomatic aortic stenosis recruited between April 2012 and May 2015. MAIN OUTCOME MEASURES: Incidence of new cerebral microinfarction and objective decline in neurocognitive performance. RESULTS: All underwent cerebral MRI at baseline and immediately following TAVI, and 49 (25 Lotus, 24 CoreValve) completed neurocognitive assessments at baseline, 30 days and 1 year. There was a significantly greater incidence of new cerebral microinfarction observed following the Lotus TAVI (23 (79%) vs 22 (59%), p=0.025) with a greater number of new infarcts per patient (median 3.5 (IQR 7.0) vs 2.0 (IQR 3.0), p=0.002). The mean volume of infarcted cerebral tissue per patient was equivalent following the two prostheses (p=0.166). More patients suffered new anterior (14 (48%) vs 2 (5%), p=0.001) and vertebrobasilar (15 (52%) vs 7 (19%), p=0.005) lesions following Lotus. Lotus was associated with a decline in verbal memory and psychomotor speed at 30 days. However, performance longitudinally at 1 year was preserved in all neurocognitive domains. CONCLUSIONS: There was a higher incidence of silent cerebral microinfarction and a greater number of lesions per patient following Lotus compared with CoreValve. However, there was no objective decline in neurocognitive function discernible at 1 year following TAVI with either prosthesis.

Aortic stiffness in aortic stenosis assessed by cardiovascular MRI: a comparison between bicuspid and tricuspid valves.

OBJECTIVES: To compare aortic size and stiffness parameters on MRI between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients with aortic stenosis (AS). METHODS: MRI was performed in 174 patients with asymptomatic moderate-severe AS (mean AVAI 0.57 ± 0.14 cm2/m2) and 23 controls on 3T scanners. Valve morphology was available/analysable in 169 patients: 63 BAV (41 type-I, 22 type-II) and 106 TAV. Aortic cross-sectional areas were measured at the level of the pulmonary artery bifurcation. The ascending and descending aorta (AA, DA) distensibility, and pulse wave velocity (PWV) around the aortic arch were calculated. RESULTS: The AA and DA areas were lower in the controls, with no difference in DA distensibility or PWV, but slightly lower AA distensibility than in the patient group. With increasing age, there was a decrease in distensibility and an increase in PWV. After correcting for age, the AA maximum cross-sectional area was higher in bicuspid vs. tricuspid patients (12.97 [11.10, 15.59] vs. 10.06 [8.57, 12.04] cm2, p < 0.001), but there were no significant differences in AA distensibility (p = 0.099), DA distensibility (p = 0.498) or PWV (p = 0.235). Patients with BAV type-II valves demonstrated a significantly higher AA distensibility and lower PWV compared to type-I, despite a trend towards higher AA area. CONCLUSIONS: In patients with significant AS, BAV patients do not have increased aortic stiffness compared to those with TAV despite increased ascending aortic dimensions. Those with type-II BAV have less aortic stiffness despite greater dimensions. These results demonstrate a dissociation between aortic dilatation and stiffness and suggest that altered flow patterns may play a role. KEY POINTS: • Both cellular abnormalities secondary to genetic differences and abnormal flow patterns have been implicated in the pathophysiology of aortic dilatation and increased vascular complications associated with bicuspid aortic valves (BAV). • We demonstrate an increased ascending aortic size in patients with BAV and moderate to severe AS compared to TAV and controls, but no difference in aortic stiffness parameters, therefore suggesting a dissociation between dilatation and stiffness. • Sub-group analysis showed greater aortic size but lower stiffness parameters in those with BAV type-II AS compared to BAV type-I.

CMR quantitation of change in mitral regurgitation following transcatheter aortic valve replacement (TAVR): impact on left ventricular reverse remodeling and outcome.

Current echocardiographic data reporting the impact of concomitant mitral regurgitation (MR) on outcome in patients who undergo transcatheter aortic valve replacement (TAVR) are conflicting. Using cardiovascular magnetic resonance (CMR) imaging, this study aimed to assess the impact of MR severity on cardiac reverse remodeling and patient outcome. 85 patients undergoing TAVR with CMR pre- and 6 m post-TAVR were evaluated. The CMR protocol included cines for left (LV) and right ventricular (RV) volumes, flow assessment, and myocardial scar assessment by late gadolinium enhancement (LGE). Patients were dichotomised according to CMR severity of MR fraction at baseline ('non-significant' vs 'significant') and followed up for a median duration of 3 years. Forty-two (49%) patients had 'significant MR' at baseline; they had similar LV and RV size and function compared to the 'non-significant MR' group but had greater LV mass at baseline. In those with significant MR at baseline, 77% (n = 32) had a reduction in MR post-TAVR, moving them into the 'non-significant' category at 6-months, with an overall reduction in MR fraction from 34 to 17% (p < 0.001). Improvement in MR was not associated with more favourable cardiac reverse remodeling when compared with the 'non-improvers'. Significant MR at baseline was not associated with increased mortality at follow-up. Significant MR is common in patients undergoing TAVR and improves in the majority post-procedure. Improvement in MR was not associated with more favourable LV reverse remodeling and baseline MR severity was not associated with mortality.

Cardiovascular magnetic resonance assessment of 1st generation CoreValve and 2nd generation Lotus valves.

OBJECTIVES: We sought to compare using serial CMR, the quantity of AR and associated valve hemodynamics, following the first-generation CoreValve (Medtronic, Minneapolis, MN) and the second-generation Lotus valve (Boston Scientific, Natick, MA). BACKGROUND: Aortic regurgitation (AR) following Transcatheter Aortic Valve Replacement (TAVR) confers a worse prognosis and can be accurately quantified using cardiovascular magnetic resonance (CMR). Second generation valves have been specifically designed to reduce paravalvular AR and improve clinical outcomes. METHODS: Fifty-one patients (79.0 ± 7.7 years, 57% male) were recruited and imaged at three time points: immediately pre- and post-TAVR, and at 6 months. RESULTS: CMR-derived AR fraction immediately post-TAVR was greater in the CoreValve compared to Lotus group (11.7 ± 8.4 vs. 4.3 ± 3.4%, P = 0.001), as was the frequency of ≥moderate AR (9/24 (37.5%) versus 0/27, P < 0.001). However, at 6 months AR fraction had improved significantly in the CoreValve group such that the two valve designs were comparable (6.4 ± 5.0 vs 5.6 ± 5.3%, P = 0.623), with no patient in either group having ≥moderate AR. The residual peak pressure gradient immediately following TAVR was significantly lower with CoreValve compared to Lotus (14.1 ± 5.6 vs 25.4 ± 11.6 mmHg, P = 0.001), but again by 6 months the two valve designs were comparable (16.5 ± 9.4 vs 19.7 ± 10.5 mmHg, P = 0.332). There was no difference in the degree of LV reverse remodeling between the two valves at 6 months. CONCLUSION: Immediately post-TAVR, there was significantly less AR but a higher residual peak pressure gradient with the Lotus valve compared to CoreValve. However, at 6 months both devices had comparable valve hemodynamics and LV reverse remodeling.

Myocardial strain and symptom severity in severe aortic stenosis: insights from cardiovascular magnetic resonance.

BACKGROUND: Symptomatic severe aortic stenosis (AS) is a class I indication for replacement in patients when left ventricular ejection fraction (LVEF) is preserved. However, symptom reporting is often equivocal and decision making can be challenging. We aimed to quantify myocardial deformation using cardiovascular magnetic resonance (CMR) in patients classified by symptom severity. METHODS: Forty-two patients with severe AS referred to heart valve clinic were studied using tagged CMR imaging. All had preserved LVEF. Patients were grouped by symptoms as either "none/mild" (n=21, NYHA class I, II) or "significant" (n=21, NYHA class III, IV, angina, syncope) but were comparable for age (72.8±5.4 vs. 71.0±6.8 years old, P=0.345), surgical risk (EuroSCORE II: 1.90±1.7 vs. 1.31±0.4, P=0.302) and haemodynamics (peak aortic gradient: 55.1±20.8 vs. 50.4±15.6, P=0.450). Thirteen controls matched in age and LVEF were also studied. LV circumferential strain was calculated using inTag© software and longitudinal strain using feature tracking analysis. RESULTS: Compared to healthy controls, patients with severe AS had significantly worse longitudinal and circumferential strain, regardless of symptom status. Patients with "significant" symptoms had significantly worse peak longitudinal systolic strain rates (-83.352±24.802%/s vs. -106.301±43.276%/s, P=0.048) than those with "no/mild" symptoms, with comparable peak longitudinal strain (PLS), peak circumferential strain and systolic and diastolic strain rates. CONCLUSIONS: Patients with severe AS who have no or only mild symptoms exhibit comparable reduction in circumferential and longitudinal fibre function to those with significant symptoms, in whom AVR is clearly indicated. Given these findings of equivalent subclinical dysfunction, reportedly borderline symptoms should be handled cautiously to avoid potentially adverse delays in intervention.

The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling.

BACKGROUND: Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling. METHODS: 48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking. RESULTS: In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m2, p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months. CONCLUSION: TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population.

Concurrent subarachnoid haemorrhage and ST elevation myocardial infarction.

Rare case of concurrent subarachnoid haemorrhage and ST elevation myocardial infarction, highlighting the importance of detailed history in an emergency.

Cardiovascular magnetic resonance evaluation of symptomatic severe aortic stenosis: association of circumferential myocardial strain and mortality.

BACKGROUND: It is unknown whether circumferential strain is associated with prognosis after treatment of aortic stenosis (AS). We aimed to characterise strain in severe AS, using myocardial tagging cardiovascular magnetic resonance (CMR), prior to and following Transcatheter Aortic Valve Implantation (TAVI) and Surgical Aortic Valve Replacement (SAVR), and determine whether abnormalities in strain were associated with outcome. METHODS: CMR was performed pre- and 6 m post-intervention in 98 patients (52 TAVI, 46 SAVR; 77 ± 8 years) with severe AS. TAVI patients were older (80.9 ± 6.4 vs. 73.0 ± 7.0 years, p < 0.01) with a higher STS score (2.06 ± 0.6 vs. 6.03 ± 3.4, p < 0.001). Tagged cine images were acquired at the basal, mid and apical LV levels with a complementary spatial modulation of magnetization (CSPAMM) pulse sequence. Circumferential strain, strain rate and rotation were calculated using inTag© software. RESULTS: No significant change in basal or mid LV circumferential strain, or of diastolic strain rate, was seen following either intervention. However, a significant and comparable decline in LV torsion and twist was observed (SAVR: torsion 14.08 ± 8.40 vs. 7.81 ± 4.51, p < 0.001, twist 16.17 ± 7.01 vs.12.45 ± 4.78, p < 0.01; TAVI: torsion 14.43 ± 4.66 vs. 11.20 ± 4.62, p < 0.001, twist 16.08 ± 5.36 vs. 12.36 ± 5.21, p < 0.001) which likely reflects an improvement towards normal physiology following relief of AS. Over a maximum 6.0y follow up, there were 23 (16%) deaths following valve intervention. On multivariable Cox analysis, baseline mid LV circumferential strain was significantly associated with all-cause mortality (hazard ratio, 1.03; 1.01-1.05; p = 0.009) independent of age, LV ejection fraction and STS mortality risk score. ROC analysis indicated a mid LV circumferential strain > -18.7% was associated with significantly reduced survival. CONCLUSION: TAVI and SAVR procedures are associated with comparable declines in rotational LV mechanics at 6 m, with largely unchanged strain and strain rates. Pre-operative peak mid LV circumferential strain is associated with post-operative mortality.

Post-procedural myocardial infarction following surgical aortic valve replacement and transcatheter aortic valve implantation.

AIMS: Myocardial injury assessed using cardiac biomarker release is ubiquitous following surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI), preventing accurate discrimination between focal myocardial infarction (MI) and global injury. Cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) imaging was used to compare rates of new MI following SAVR and TAVI. METHODS AND RESULTS: Identical CMR scans were obtained at baseline and six months post procedure in ninety-six patients undergoing SAVR (n=39) and TAVI (n=57). The rate of new MI was greater following SAVR than TAVI (SAVR, n=10 [26%] vs. TAVI, n=3 [5%], p=0.004). Infarct mass was similar between groups (SAVR 1.1±0.6 vs. TAVI 2.0±1.4 g, p=0.395). New MI did not impact on change in LV ejection fraction (SAVR:LGE[+]2.2±4.7 vs. LGE[-]0.9±8.0%, p=0.437, TAVI:LGE[+]-0.9±6.0 vs. LGE[-]2.0±7.8%, p=0.420). Thirty-four patients (60%) in the TAVI group had non-revascularised coronary artery disease (CAD) at the time of TAVI, of whom three (9%) had new MI. CONCLUSIONS: MI is an infrequent complication of TAVI but is more common following SAVR. Infarct size is small following both procedures. The low new infarct rate in TAVI, especially in the context of high rates of non-revascularised CAD, strengthens data from previous studies suggesting that coronary revascularisation pre-TAVI may be unnecessary.

Myocardial Extracellular Volume Estimation by CMR Predicts Functional Recovery Following Acute MI.

OBJECTIVES: In the setting of reperfused acute myocardial infarction (AMI), the authors sought to compare prediction of contractile recovery by infarct extracellular volume (ECV), as measured by T1-mapping cardiac magnetic resonance (CMR), with late gadolinium enhancement (LGE) transmural extent. BACKGROUND: The transmural extent of myocardial infarction as assessed by LGE CMR is a strong predictor of functional recovery, but accuracy of the technique may be reduced in AMI. ECV mapping by CMR can provide a continuous measure associated with the severity of tissue damage within infarcted myocardium. METHODS: Thirty-nine patients underwent acute (day 2) and convalescent (3 months) CMR scans following AMI. Cine imaging, tissue tagging, T2-weighted imaging, modified Look-Locker inversion T1 mapping natively and 15 min post-gadolinium-contrast administration, and LGE imaging were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF), and strain were compared per-segment and per-patient. RESULTS: Per-segment, acute ECV and LGE transmural extent were associated with convalescent wall motion score (p < 0.01; p < 0.01, respectively). ECV had higher accuracy than LGE extent to predict improved wall motion (area under receiver-operating characteristics curve 0.77 vs. 0.66; p = 0.02). Infarct ECV ≤0.5 had sensitivity 81% and specificity 65% for prediction of improvement in segmental function; LGE transmural extent ≤0.5 had sensitivity 61% and specificity 71%. Per-patient, ECV and LGE correlated with convalescent wall motion score (r = 0.45; p < 0.01; r = 0.41; p = 0.02, respectively) and convalescent EF (p < 0.01; p = 0.04). ECV and LGE extent were not significantly correlated (r = 0.34; p = 0.07). In multivariable linear regression analysis, acute infarct ECV was independently associated with convalescent infarct strain and EF (p = 0.03; p = 0.04), whereas LGE was not (p = 0.29; p = 0.24). CONCLUSIONS: Acute infarct ECV in reperfused AMI can complement LGE assessment as an additional predictor of regional and global LV functional recovery that is independent of transmural extent of infarction.

Acute Reverse Remodelling After Transcatheter Aortic Valve Implantation: A Link Between Myocardial Fibrosis and Left Ventricular Mass Regression.

BACKGROUND: Despite the wealth of data showing the positive effects on cardiac reverse remodelling in the long-term, the immediate effects of transcatheter aortic valve implantation (TAVI) on the left ventricle are yet to be comprehensively described using cardiovascular magnetic resonance imaging. Also, the link between myocardial fibrosis and acute left ventricular (LV) mass regression is unknown. METHODS: Fifty-seven patients with severe aortic stenosis awaiting TAVI underwent paired cardiovascular magnetic resonance scans before and early after the procedure (4 [interquartile range, 3-5] days). LV mass, volume, and function were measured. Late gadolinium enhancement (LGE) imaging was performed to assess for the presence of and pattern of myocardial fibrosis. RESULTS: After the procedure, 53 (95%) patients experienced an immediate (10.1 ± 7.1%) reduction in indexed LV mass (LVMi) from 76 ± 15.5 to 68.4 ± 14.7 g/m2 (P < 0.001). Those with no LGE experienced the greatest LVMi regression (13.9 ± 7.1%) compared with those with a midwall/focal fibrosis pattern LGE (7.4 ± 5.8%) and infarct pattern LGE (7.2 ± 7.0%; P = 0.005). There was no overall change in LV ejection fraction (LVEF; 55.1 ± 12.1% to 55.5 ± 10.9%; P = 0.867), however a significant improvement in LVEF was seen in those with abnormal (< 55%; n = 24; 42%) baseline LVEF (43.2 ± 8.9 to 46.7 ± 10.5%; P = 0.027). Baseline LVMi (P = 0.005) and myocardial fibrosis (P < 0.001) were strong independent predictors of early LVMi regression. CONCLUSIONS: LV reverse remodelling occurs immediately after TAVI, with significant LV mass regression in the total population and an improvement in LVEF in those with preexisting LV impairment. Those without myocardial fibrosis at baseline experience greater LV mass regression than those with fibrosis.

Right ventricular function following surgical aortic valve replacement and transcatheter aortic valve implantation: A cardiovascular MR study.

OBJECTIVE: The response of the RV following treatment of aortic stenosis is poorly defined, reflecting the challenge of accurate RV assessment. Cardiovascular magnetic resonance (CMR) is the established reference for imaging of RV volumes, mass and function. We sought to define the impact of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) upon RV function in patients treated for severe aortic stenosis using CMR. METHODS: A 1.5T CMR scan was performed preoperatively and 6months postoperatively in 112 (56 TAVI, 56 SAVR; 76±8years) high-risk severe symptomatic aortic stenosis patients across two UK cardiothoracic centres. RESULTS: TAVI patients were older (80.4±6.7 vs. 72.8±7.2years, p<0.05) with a higher STS score (2.13±0.73 vs. 5.54±3.41%, p<0.001). At 6months, SAVR was associated with a significant increase in RV end systolic volume (33±10 vs. 37±10ml/m2, p=0.008), and decrease in RV ejection fraction (58±8 vs. 53±8%, p=0.005) and tricuspid annular plane systolic excursion (22±5 vs. 14±3mm, p<0.001). Only 4 (7%) SAVR patients had new RV late gadolinium hyper-enhancement with no new cases seen in the TAVI patients at 6months. Longer surgical cross-clamp time was the only predictor of increased RV end systolic volume at 6months. Post-TAVI, there was no observed change in RV volumes or function. Over a maximum 6.3year follow-up, 18(32%) of TAVI patients and 1(1.7%) of SAVR patients had died (p=0.001). On multivariable Cox analysis, the RV mass at 6m post-TAVI was independently associated with all-cause mortality (HR 1.359, 95% CI 1.108-1.666, p=0.003). CONCLUSIONS: SAVR results in a deterioration in RV systolic volumes and function associated with longer cross-clamp times and is not fully explained by suboptimal RV protection during cardiopulmonary bypass. TAVI had no adverse impact upon RV volumes or function.

Assessment of aortic stiffness by cardiovascular magnetic resonance following the treatment of severe aortic stenosis by TAVI and surgical AVR.

BACKGROUND: Aortic stiffness is increasingly used as an independent predictor of adverse cardiovascular outcomes. We sought to compare the impact of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) upon aortic vascular function using cardiovascular magnetic resonance (CMR) measurements of aortic distensibility and pulse wave velocity (PWV). METHODS AND RESULTS: A 1.5 T CMR scan was performed pre-operatively and at 6 m post-intervention in 72 patients (32 TAVI, 40 SAVR; age 76 ± 8 years) with high-risk symptomatic severe aortic stenosis. Distensibility of the ascending and descending thoracic aorta and aortic pulse wave velocity were determined at both time points. TAVI and SAVR patients were comparable for gender, blood pressure and left ventricular ejection fraction. The TAVI group were older (81 ± 6.3 vs. 72.8 ± 7.0 years, p < 0.05) with a higher EuroSCORE II (5.7 ± 5.6 vs. 1.5 ± 1.0 %, p < 0.05). At 6 m, SAVR was associated with a significant decrease in distensibility of the ascending aorta (1.95 ± 1.15 vs. 1.57 ± 0.68 × 10(-3)mmHg(-1), p = 0.044) and of the descending thoracic aorta (3.05 ± 1.12 vs. 2.66 ± 1.00 × 10(-3)mmHg(-1), p = 0.018), with a significant increase in PWV (6.38 ± 4.47 vs. 11.01 ± 5.75 ms(-1), p = 0.001). Following TAVI, there was no change in distensibility of the ascending aorta (1.96 ± 1.51 vs. 1.72 ± 0.78 × 10(-3)mmHg(-1), p = 0.380), descending thoracic aorta (2.69 ± 1.79 vs. 2.21 ± 0.79 × 10(-3)mmHg(-1), p = 0.181) nor in PWV (8.69 ± 6.76 vs. 10.23 ± 7.88 ms(-1), p = 0.301) at 6 m. CONCLUSIONS: Treatment of symptomatic severe aortic stenosis by SAVR but not TAVI was associated with an increase in aortic stiffness at 6 months. Future work should focus on the prognostic implication of these findings to determine whether improved patient selection and outcomes can be achieved.

Sex-related differences in left ventricular remodeling in severe aortic stenosis and reverse remodeling after aortic valve replacement: A cardiovascular magnetic resonance study.

BACKGROUND: Cardiac adaptation to aortic stenosis (AS) appears to differ according to sex, but reverse remodeling after aortic valve replacement has not been extensively described. The aim of the study was to determine using cardiac magnetic resonance imaging whether any sex-related differences exist in AS in terms of left ventricular (LV) remodeling, myocardial fibrosis, and reverse remodeling after valve replacement. METHODS: One hundred patients (men, n = 60) with severe AS undergoing either transcatheter or surgical aortic valve replacement underwent cardiac magnetic resonance scans at baseline and 6 months after valve replacement. RESULTS: Despite similar baseline comorbidity and severity of AS, women had a lower indexed LV mass than did men (65.3 ± 18.4 vs 81.5 ± 21.3 g/m(2), P < .001) and a smaller indexed LV end-diastolic volume (87.3 ± 17.5 vs 101.2 ± 28.6 mL/m(2), P = .002) with a similar LV ejection fraction (58.6% ± 10.2% vs 54.8% ± 12.9%, P = .178). Total myocardial fibrosis mass was similar between sexes (2.3 ± 4.1 vs 1.3 ± 1.1 g, P = .714), albeit with a differing distribution according to sex. After aortic valve replacement, men had more absolute LV mass regression than did women (18.3 ± 10.6 vs 12.7 ± 8.8 g/m(2), P = .007). When expressed as a percentage reduction of baseline indexed LV mass, mass regression was similar between the sexes (men 21.7% ± 10.1% vs women 18.4% ± 11.0%, P = .121). There was no sex-related difference in postprocedural LV ejection fraction or aortic regurgitation. Sex was not found to be a predictor of LV reverse remodeling on multiple regression analysis. CONCLUSIONS: There are significant differences in the way that male and female hearts adapt to AS. Six months after aortic valve replacement, there are no sex-related differences in reverse remodeling, but superior reverse remodeling in men as a result of their more adverse remodeling profile at baseline.

Cardiac remodelling and function with primary mitral valve insufficiency studied by magnetic resonance imaging.

AIMS: Evaluation of patients with primary mitral valve insufficiency (MI) is best supported by quantitative measures. Cardiovascular magnetic resonance imaging (CMR) offers flow and cardiac chamber volume quantification. We studied cardiac remodelling with CMR to determine MI regurgitation volumes (MIVol) related to severe MI. METHODS AND RESULTS: In total, 24, 20, and 28 patients determined to have mild, moderate, and severe primary MI, respectively, were studied. Combining cine stacks with phase-contrast velocity mapping across the ascending aorta, CMR-determined MIVol was reproducibly obtained as the difference between left ventricular (LV) stroke volume and aortic forward flow (Aoflow). With increasing MI severity, MIVol, left heart volumes, and pulmonary venous diameters increased (P < 0.01). Severe MI with LV end-systolic diameter of 40 mm was signified by MIVol >40 mL, MI regurgitant fraction >0.30, LV end-diastolic volume (LVEDV(i)) >108 mL m(-2), and a total left heart volume >188 mL m(-2) with dilated pulmonary veins and a LVEDV/right ventricular EDV ratio >1.2. In severe MI, LV ejection fraction was unaffected, but the Aoflow and the peak ejection rate indexed to LVEDV were lowered (P < 0.05). In surgical patients, the MIVol correlated to the decrease in LV dimension after valve surgery (P < 0.02). CONCLUSION: CMR provides a reproducible quantitative technique for evaluation of MI, as MIVol and cardiac chamber volumes can be held against diagnostic cut-off values. The Aoflow and peak ejection rate indexed to LVEDV may reveal early LV systolic dysfunction in patients with severe MI. Severe MI is related to lower MI regurgitation volume and fraction than previously believed.

Patient adaptive maximal resolution magnetic resonance myocardial stress perfusion imaging.

PURPOSE: To demonstrate the feasibility of an automatic adaptive acquisition sequence. Magnetic resonance perfusion pulse sequences often leave potential acquisition time unused in patients with lower heart-rates (HR) and smaller body size. MATERIALS AND METHODS: A perfusion technique was developed that automatically adapts to HR and field-of-view by maximizing in-plane spatial resolution while maintaining temporal resolution every cardiac cycle. Patients (n = 10) and volunteers (n = 10) were scanned with both a standard resolution and adaptive method. Image quality was scored, signal-to-noise ratio (SNR) calculated, and width of dark-rim artifact (DRA) measured. RESULTS: The acquired spatial resolution of the adaptive sequence (1.92 × 1.92 mm(2) ± 0.34) was higher than the standard resolution (2.42 × 2.42 mm(2) ) (P < 0.0001). Mean DRA width was reduced using the adaptive pulse sequence (1.94 ± 0.60 mm vs. 2.82 ± 0.65 mm, P < 0.0001). The signal-to-noise ratio (SNR) was higher with the standard pulse sequence (6.7 ± 2.2 vs. 3.8 ± 1.8, P < 0.0001). There was no difference in image quality score between sequences in either volunteers (1.1 ± 0.31 vs. 1.0 ± 0.0, P = 0.34) or patients (1.3 ± 0.48 vs. 1.3 ± 0.48, P = 1.0). CONCLUSION: Optimizing the use of available imaging time during first-pass perfusion with a magnetic resonance imaging pulse sequence that adapts image acquisition duration to HR and patient size is feasible. Acquired in-plane spatial resolution is improved, the DRA is reduced, and while SNR is reduced with the adaptive sequence consistent with the lower voxel size used, image quality is maintained.

Consequence of cerebral embolism after transcatheter aortic valve implantation compared with contemporary surgical aortic valve replacement: effect on health-related quality of life.

BACKGROUND: Incidence of cerebral microinfarcts is higher after transcatheter aortic valve implantation (TAVI) compared with surgical aortic valve replacement (SAVR). It is unknown whether these lesions persist and what direct impact they have on health-related quality of life. The objective was to identify predictors of cerebral microinfarction and measure their effect on health-related quality of life during 6 months after TAVI when compared with SAVR. METHODS AND RESULTS: Cerebral MRI was conducted at baseline, post procedure, and 6 months using diffusion-weighted imaging. Health-related quality of life was measured at baseline, 30 days, and 6 months with short form-12 health outcomes and EuroQol 5 dimensions questionnaires. One hundred eleven patients (TAVI, n=71; SAVR, n=40) were studied. The incidence (54 [77%] versus 17 [43%]; P=0.001) and number (3.4±4.9 versus 1.2±1.8; P=0.001) of new microinfarcts were greater after TAVI than after SAVR. The total volume per microinfarct was smaller in TAVI than in SAVR (0.23±0.24 versus 0.76±1.8 mL; P=0.04). The strongest associations for microinfarction were: TAVI (arch atheroma grade: r=0.46; P=0.0001) and SAVR (concomitant coronary artery bypass grafting: r=-0.33; P=0.03). Physical component score in TAVI increased after 30 days (32.1±6.6 versus 38.9±7.0; P<0.0001) and 6 months (40.4±9.3; P<0.0001); the improvement occurred later in SAVR (baseline: 34.9±10.6; 30 days: 35.9±10.2; 6 months: 42.8±11.2; P<0.001). After TAVI, there were no differences in the short form-12 health outcome scores according to the presence or size of new cerebral infarction. CONCLUSIONS: Cerebral microinfarctions are more common after TAVI compared with SAVR but seem to have no negative effect on early (30 days) or medium term (6 months) health-related quality of life. Aortic atheroma (TAVI) and concomitant coronary artery bypass grafting (SAVR) are independent risk factors for cerebral microinfarction.

Quantification of myocardial blood flow with cardiovascular magnetic resonance throughout the cardiac cycle.

BACKGROUND: Myocardial blood flow (MBF) varies throughout the cardiac cycle in response to phasic changes in myocardial tension. The aim of this study was to determine if quantitative myocardial perfusion imaging with cardiovascular magnetic resonance (CMR) can accurately track physiological variations in MBF throughout the cardiac cycle. METHODS: 30 healthy volunteers underwent a single stress/rest perfusion CMR study with data acquisition at 5 different time points in the cardiac cycle (early-systole, mid-systole, end-systole, early-diastole and end-diastole). MBF was estimated on a per-subject basis by Fermi-constrained deconvolution. Interval variations in MBF between successive time points were expressed as percentage change. Maximal cyclic variation (MCV) was calculated as the percentage difference between maximum and minimum MBF values in a cardiac cycle. RESULTS: At stress, there was significant variation in MBF across the cardiac cycle with successive reductions in MBF from end-diastole to early-, mid- and end-systole, and an increase from early- to end-diastole (end-diastole: 4.50 ± 0.91 vs. early-systole: 4.03 ± 0.76 vs. mid-systole: 3.68 ± 0.67 vs. end-systole 3.31 ± 0.70 vs. early-diastole: 4.11 ± 0.83 ml/g/min; all p values <0.0001). In all cases, the maximum and minimum stress MBF values occurred at end-diastole and end-systole respectively (mean MCV = 26 ± 5%). There was a strong negative correlation between MCV and peak heart rate at stress (r = -0.88, p < 0.001). The largest interval variation in stress MBF occurred between end-systole and early-diastole (24 ± 9% increase). At rest, there was no significant cyclic variation in MBF (end-diastole: 1.24 ± 0.19 vs. early-systole: 1.28 ± 0.17 vs.mid-systole: 1.28 ± 0.17 vs. end-systole: 1.27 ± 0.19 vs. early-diastole: 1.29 ± 0.19 ml/g/min; p = 0.71). CONCLUSION: Quantitative perfusion CMR can be used to non-invasively assess cyclic variations in MBF throughout the cardiac cycle. In this study, estimates of stress MBF followed the expected physiological trend, peaking at end-diastole and falling steadily through to end-systole. This technique may be useful in future pathophysiological studies of coronary blood flow and microvascular function.

The distribution and prognosis of anomalous coronary arteries identified by cardiovascular magnetic resonance: 15 year experience from two tertiary centres.

BACKGROUND: Aberrant coronary arteries represent a diverse group of congenital disorders. Post-mortem studies reveal a high risk of exercise-related sudden cardiac death in those with an anomalous coronary artery originating from the opposite sinus of Valsalva (ACAOS) with an inter-arterial course. There is little documentation of lifetime history and long-term follow-up of patients with coronary artery anomalies. METHODS: Patients with anomalous coronary arteries undergoing cardiovascular magnetic resonance over a 15-year period were identified and classified by anatomy and course. Medical records were reviewed for major adverse cardiovascular events (MACE). Revascularisation or myocardial infarction counted only if occurring in the distribution of the anomalous artery. RESULTS: Consecutive patients with coronary artery anomalies were retrospectively identified (n = 172). Median follow-up time was 4.3 years (IQR 2.5-7.8, maximum 15.6). 116 patients had ACAOS of which 64 (55%) had an inter-arterial course (IAC) and 52 (45%) did not. During follow up 110 ACAOS patients were alive, 5 died and 1 lost to follow-up.ACAOS patients experienced 58 MACE events (5 cardiovascular deaths, 5 PCI, 24 CABG and 24 had myocardial infarction). 47 MACE events occurred in ACAOS with IAC and 11 in those without (p < 0.0001), the statistical difference driven by surgical revascularisation and myocardial infarction. CONCLUSIONS: In life, patients with an anomalous coronary artery originating from the opposite sinus of Valsalva taking an IAC have higher rates of both myocardial infarction and surgical revascularisation during long-term follow up, compared to those without IAC.