ObjectiveInoperable chronic thromboembolic pulmonary hypertension (CTEPH) managed medically has a poor prognosis. Balloon pulmonary angioplasty (BPA) offers a new treatment for inoperable patients. The national BPA service for the UK opened in October 2015 and we now describe the treatment of our initial patient cohort.MethodsThirty consecutive, inoperable, anatomically suitable, symptomatic patients on stable medical therapy for CTEPH were identified and offered BPA. They initially underwent baseline investigations including Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) quality of life (QoL) questionnaire, cardiopulmonary exercise test, 6 min walk distance (6MWD), transthoracic echocardiography, N-terminal probrain natriuretic peptide (NT pro-BNP) and right heart catheterisation. Serial BPA sessions were then performed and after completion, the treatment effect was gauged by comparing the same investigations at 3 months follow-up.ResultsA median of 3 (IQR 1–6) BPA sessions per patient resulted in a significant improvement in functional status (WHO functional class ≥3: 24 vs 4, p<0.0001) and QoL (CAMPHOR symptom score: 8.7±5.4 vs 5.6±6.1, p=0.0005) with reductions in pulmonary pressures (mean pulmonary artery pressure: 44.7±11.0 vs 34.4±8.3 mm Hg, p<0.0001) and resistance (pulmonary vascular resistance: 663±281 vs 436±196 dyn.s.cm-5, p<0.0001). Exercise capacity improved (minute ventilation/carbon dioxide production: 55.3±12.2 vs 45.0±7.8, p=0.03 and 6MWD: 366±107 vs 440±94 m, p<0.0001) and there was reduction in right ventricular (RV) stretch (NT pro-BNP: 442 (IQR 168–1607) vs 202 (IQR 105–447) pg/mL, p<0.0001) and dimensions (mid RV diameter: 4.4±1.0 vs 3.8±0.7 cm, p=0.002). There were no deaths or life-threatening complications and the mild-moderate per-procedure complication rate was 10.5%.ConclusionsBPA is safe and improves the functional status, QoL, pulmonary haemodynamics and RV dimensions of patients with inoperable CTEPH.

There is renewed interest in the haemodynamic definitions of pulmonary hypertension (PH), reigniting an old debate about diagnostic thresholds [1]. Recent prospective data support work dating back over 40 years demonstrating patients with "borderline" PH (mean pulmonary artery pressure (mPAP) <25 mmHg) can still have significant morbidity and mortality [2]. Therefore, lowering the mPAP threshold for the diagnosis of precapillary pulmonary arterial hypertension (PAH) has been discussed at World Symposium on Pulmonary Hypertension in Nice, France, in 2018. A potentially different approach has arisen in group 4 (chronic thromboembolic pulmonary hypertension (CTEPH)), where the concept of chronic thromboembolic disease without PH (CTED) has gained traction. This describes a population of patients with mPAP <25 mmHg, with no lower limit, who have persistent vascular obstructions, impaired response to exercise, and a high impact of disease on symptoms and quality of life (QoL). The 25-mmHg threshold is important partly because it excludes patients who might benefit from treatment, and then precludes their participation in clinical trials, forming a cycle that prevents regulatory approved treatment in the future. In the CTED to CTEPH spectrum, it is unclear if reducing the threshold is the best way to address this inequity, as minimal data exists detailing outcomes <25 mmHg. In the UK, we have undertaken pulmonary endarterectomy (PEA) on a selected, symptomatic cohort of operable CTED patients with good results [3], which were recapitulated by others [4,5]. A valid criticism of our previous work [3] is the retrospective, selective nature of the subjects and a lack of understanding about the natural history of the disease without treatment. Here, we present the first prospective cohort of patients with operable CTED (institutional review board project reference S02297), and hypothesised that clinically meaningful symptoms, limitation and physiology would relate to haemodynamics. Royal Papworth Hospital (Cambridge, UK) is the national PEA referral centre and to minimise tertiary speciality referral bias, we have included only regional nonspecialist referrals. Regional incident cases referred in 2015-2017 with suspected CTED/CTEPH were prospectively assessed. All patients were reviewed at the national CTEPH multidisciplinary team (MDT) meeting. Patients with operable CTED underwent standard CTEPH investigations [6] with additional exercise right heart catheterisation (RHC) and incremental cardiopulmonary exercise testing (CPET) [7]. The zero reference was set at the midthoracic level. During exercise RHC, patients were asked to pedal for 5 min at 40% of the workload achieved during incremental CPET (load range 9-104 W, maximal supine exercise test could not been performed due to technical limitation of ergometer). The mPAP, pulmonary wedge pressure (measured over three breath cycles, when feasible), mixed venous saturation, heart rate and systemic blood pressure were measured, followed by cardiac output (CO) measurement us...

Right atrial pressure (RAP) is a key cardiac parameter of diagnostic and prognostic significance, yet current two-dimensional echocardiographic methods are inadequate for the accurate estimation of this haemodynamic marker. Right-heart trans-tricuspid Doppler and tissue Doppler echocardiographic techniques can be combined to calculate the right ventricular (RV) E/e′ ratio–a reflection of RV filling pressure which is a surrogate of RAP. A systematic search was undertaken which found seventeen articles that compared invasively measured RAP with RV-E/e′ estimated RAP. Results commonly concerned pulmonary hypertension or advanced heart failure/transplantation populations. Reported receiver operating characteristic analyses showed reasonable diagnostic ability of RV-E/e′ for estimating RAP in patients with coronary artery disease and RV systolic dysfunction. The diagnostic ability of RV-E/e′ was generally poor in studies of paediatrics, heart failure and mitral stenosis, whilst results were equivocal in other diseases. Bland–Altman analyses showed good accuracy but poor precision of RV-E/e′ for estimating RAP, but were limited by only being reported in seven out of seventeen articles. This suggests that RV-E/e′ may be useful at a population level but not at an individual level for clinical decision making. Very little evidence was found about how atrial fibrillation may affect the estimation of RAP from RV-E/e′, nor about the independent prognostic ability of RV-E/e′. Recommended areas for future research concerning RV-E/e′ include; non-sinus rhythm, valvular heart disease, short and long term prognostic ability, and validation over a wide range of RAP.

Aims  Altered left atrial (LA) blood flow characteristics account for an increase in cardioembolic stroke risk in atrial fibrillation (AF). Here, we aimed to assess whether exposure to stroke risk factors is sufficient to alter LA blood flow even in the presence of sinus rhythm (SR). Methods and results  We investigated 95 individuals: 37 patients with persistent AF, who were studied before and after cardioversion [Group 1; median CHA2DS2-VASc = 2.0 (1.5–3.5)]; 35 individuals with no history of AF but similar stroke risk to Group 1 [Group 2; median CHA2DS2-VASc = 3.0 (2.0–4.0)]; and 23 low-risk individuals in SR [Group 3; median CHA2DS2-VASc = 0.0 (0.0–0.0)]. Cardiac function and LA flow characteristics were evaluated using cardiac magnetic resonance. Before cardioversion, Group 1 displayed impaired left ventricular (LV) and LA function, reduced LA flow velocities and vorticity, and a higher normalized vortex volume (all P &lt; 0.001 vs. Groups 2 and 3). After restoration of SR at ≥4-week post-cardioversion, LV systolic function and LA flow parameters improved significantly (all P &lt; 0.001 vs. pre-cardioversion) and were no longer different from those in Group 2. However, in the presence of SR, LA flow peak and mean velocity, and vorticity were lower in Groups 1 and 2 vs. Group 3 (all P &lt; 0.01), and were associated with impaired LA emptying fraction (LAEF) and LV diastolic dysfunction. Conclusion  Patients at moderate-to-high stroke risk display altered LA flow characteristics in SR in association with an LA myopathic phenotype and LV diastolic dysfunction, regardless of a history of AF.

See Article by Asch et al A quick eyeball estimate of left ventricular function is often the first thing an echocardiographer or clinician performs, whether consciously or subconsciously, when they start to perform an examination. 1 By the time they are writing their report, a precise, quantified measure will have replaced this estimate. 2 Over time, M-mode quantification 3 has been superseded by a series of new ultrasound technologies, to the point where 3D echocardiography is now accepted as providing measures as precise as cardiovascular magnetic resonance. 4 So what next? Asch et al 5 in this issue of Circulation Cardiovascular Imaging propose that echocardiography may have reached a stage in life perhaps best described by Marcel Proust in his 'Remembrance of Things Past' when he realizes that: 'the real voyage of discovery is not in seeking new landscapes but in having new eyes'. 6 The new eyes for echocardiography are those of a computer, trained using artificial intelligence (AI) methodology, to mimic a human expert's eye. To develop an AI that can eyeball left ventricular function, the team had to give some guidance to the computer. Based on the a priori observation that the operator does not rely on volume measures when they estimate left ventricular function, they trained the computer to look for proportional, rather than absolute, changes in the size of the heart. When performed along 2 orthogonal axes within the apical long-axis views these proportional changes can replace volume measures in the equations used to calculate ejection fraction. 5 The approach overcomes several technical challenges, including needing to account for image scaling when generating measures and trying to identify borders in poor quality images, which limits some other automated techniques. 7,8 The major limitation is that, because the computer performs no measures of left ventricular size, no volume or size measures are reportable with the technology and, as only 2 planes are used, unusual pathologies or regional variations are overlooked. After training on 50 000 real-world patients, the method was tested on scans from 99 new studies, which had also been analyzed by independent experts. The ability to identify patients with severe left ventricular dysfunction (ejection fraction <35%) was particularly impressive achieving sensitivity and specificity of 0.90 and 0.92, respectively. The overall performance across a range of ejection fraction levels was also good but with apparently large limits of agreement of over 10%. This degree of variation from a reference standard was similar to that recorded for clinical readers. If most of the time we are eyeballing within 5% to 10% of the right answer, is that acceptable? Some of this variation may also represent an experimental problem of comparing 2 methods, neither of which generate gold standard measures, against each other. Which is closer to the truth, the AI method or the reference method? Interestingly, on closer examination, there are subtle differences that differentiate AI e...

Cardiac diastolic dysfunction is prevalent and is a diagnostic criterion for heart failure with preserved ejection fraction—a burgeoning global health issue. As gold-standard invasive haemodynamic assessment of diastolic function is not routinely performed, clinical guidelines advise using echocardiography measures to determine the grade of diastolic function. However, the current process has suboptimal accuracy, regular indeterminate classifications and is susceptible to confounding from comorbidities. Advances in artificial intelligence in recent years have created revolutionary ways to evaluate and integrate large quantities of cardiology data. Imaging is an area of particular strength for the sub-field of machine-learning, with evidence that trained algorithms can accurately discern cardiac structures, reliably estimate chamber volumes, and output systolic function metrics from echocardiographic images. In this review, we present the emerging field of machine-learning based echocardiographic diastolic function assessment. We summarise how machine-learning has made use of diastolic parameters to accurately differentiate pathology, to identify novel phenotypes within diastolic disease, and to grade diastolic function. Perspectives are given about how these innovations could be used to augment clinical practice, whilst areas for future investigation are identified.

In pulmonary vascular disease (PVD) exercise abnormalities can include reduced exercise capacity, reduced oxygen pulse (O2 pulse) and elevated VE/VCO2. The association of clinical measures such as 6 minute walk work (6MWW), haemodynamics, lung function and echocardiogram to peak VO2, O2 pulse and VE/VCO2 has not been fully investigated in PVD Aims: To determine the relationship of 6MWW and other clinical measures to peak VO2, peak O2 pulse and VE/VCO2. Additionally, to investigate the ability to predict peak VO2 from 6MWW and other clinical parameters. Methods: Clinical data was retrospectively analysed from 63 chronic thromboembolic pulmonary hypertension (CTEPH) and 54 chronic thromboembolic disease (CTED) patients. 6 minute walk test measures, haemodynamics, lung function and echocardiographic measures were correlated with peak VO2, peak O2 pulse and VE/VCO2. Predictive equations were developed to predict peak V̇O2 in both CTEPH and CTED cohorts and subsequently validated. Results: A number of clinical parameters correlated to peak VO2, peak O2 pulse and VE/VCO2. 6MWW and TLCO demonstrated the strongest correlation to peak VO2 and peak O2 pulse. The validation of the predictive equations showed a variable level of agreement between measured peak VO2 and calculated peak VO2 from the predictive equations. Conclusion: 6MWW and additionally a number of clinical test parameters were associated to peak VO2, peak O2 pulse and VE/VCO2. 6MWW and TLCO were particularly highly correlated to peak VO2 and similarly to peak O2 pulse. The validation of the predictive equations showed a variable level of agreement and therefore may have limited clinical applicability.

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