Cost-effectiveness of screening for paroxysmal atrial fibrillation in patients undergoing echocardiography.

BACKGROUND: Screening for atrial fibrillation is recommended for patients > 65 years on current guidelines. Targeted screening may be more efficient, however the appropriate location for screening programs has not been well defined. Our aim was to compare the cost-effectiveness of unselected electrocardiographic (ECG) screening for atrial fibrillation (AF), and selective screening based on an abnormal echocardiogram. METHODS: Two strategies of portable ECG screening for AF were compared in the base case of a hypothetical asymptomatic 65-year-old man (CHA2 DS2 -VASC = 3 based on hypertension and diabetes mellitus) with previous echocardiography but without a cause for AF (e.g. mitral valve disease, left ventricular (LV) dysfunction). With age-based screening (AgeScreen; 3% AF detection rate) all patients underwent ECG. With imaging-guided screening (ImagingScreen; 5% detection rate), only patients with left atrial (LA) volume ≥34 mL/m2 and LA reservoir strain <34% or LV global longitudinal strain > -18% underwent ECG screening. A Markov model was informed by published transition probabilities, costs and quality-adjusted life years (QALY). Costs, effects and incremental cost-effectiveness ratio were assessed for each screening strategy over a 20-year period. The willingness-to-pay threshold was $53 000/QALY. RESULTS: ImagingScreen dominated AgeScreen, with a lower cost ($54 823 vs $57842) and better outcome (11.56 vs 11.52 QALY over 20 years). Monte Carlo simulation demonstrated that 61% of observations were more efficacious with ImagingScreen, with cost below willingness to pay. The main cost determinants were annual costs of stroke or heart failure and AF detection rates. ImagingScreen was more cost-effective for AF detection rates up to 14%, and more cost-effective across a range of annual stroke ($24 000-$102 000) and heart failure ($4000-$12 000) costs. CONCLUSION: In patients with a previous echocardiogram, AF screening of those with baseline clinical and imaging risk parameters is more cost-effective than age-based screening.

Association between socioeconomic status and incident atrial fibrillation.

BACKGROUND: Low socioeconomic status is associated with cardiovascular diseases, and an association with atrial fibrillation (AF) could guide screening. AIM: To investigate if indices of advantage/disadvantage (IAD), index of education/occupation (IEO) and index of economic resources were associated with incident AF, independent of risk factors and cardiac function. METHODS: We studied community-based participants aged ≥65 years with AF risk factors (n = 379, age 70 ± 4 years, 45% men). The CHARGE-AF score (a well validated AF risk score) was used to assess 5-year risk of developing AF. Participants also had baseline echocardiograms. IAD, IEO and index of economic resources were obtained from the 2011 Socio-Economic Indexes for Areas score, in which higher decile ranks indicate more advantaged areas. Patients were followed up for incident AF (median 21 (range 5-31) months), with AF diagnosed by clinical review, including 12-lead electrocardiogram (ECG), as well as single-lead portable ECG monitoring used to record 60 s ECG tracings five times/day for 1 week. Cox proportional hazards models were used to assess the association between socioeconomic status and incident AF. RESULTS: Subjects with AF (n = 50, 13%) were more likely to be male (64 vs 42%, P = 0.003) and had higher CHARGE-AF score (median 7.1% (5.2-12.8%) vs 5.3% (3.3-8.6%), P < 0.001). Areas with lower socioeconomic status (IAD and IEO) had a higher risk of incident AF independent of LV function and CHARGE-AF score (hazard ratio for IAD 1.16, 95% confidence interval 1.05-1.29, P = 0.005 and hazard ratio for IEO 1.18, 95% confidence interval 1.07-1.30, P = 0.001). CONCLUSION: Regional socioeconomic status is associated with risk of incident AF, independent of LV function and clinical risk. This association might permit better regional targeting of prevention.

NOACs Now Mainstream for the Use of Anticoagulation in Non-Valvular Atrial Fibrillation in Australia.

The management of stroke risk in patients with non-valvular atrial fibrillation has changed over the past few years. This change has occurred due to the introduction of novel oral anticoagulants (NOACs) such as apixaban, rivaroxaban and dabigatran for the management of non-valvular atrial fibrillation. These agents have shown comparable stroke risk reduction to warfarin in large international multicentre trials [1-3]. This has changed the clinical practice of many treating physicians since their introduction from 2011 to 2013. The purpose of this review was to highlight the now mainstream use of NOAC administration in preference to warfarin, by comparing the trends in the number of prescriptions filled since all three forms of oral anti-coagulant became available in 2013. These agents are being increasingly prescribed due to their ease of use compared to warfarin, which not only requires ongoing monitoring due to narrow therapeutic range but also has many drug and food interactions. Since November 2015, NOACs have become the mainstream choice for anticoagulation in atrial fibrillation likely given their ease of use compared to warfarin. The use of each anticoagulant remains divergent with the use of warfarin continuing to decrease.

Incidence and predictors of permanent pacemaker implantation following treatment with the repositionable Lotus™ transcatheter aortic valve.

OBJECTIVES: To determine the incidence and predictors of permanent pacemaker (PPM) requirement following transcatheter aortic valve replacement (TAVR) with the mechanically expanded LotusTM Valve System (Boston Scientific). BACKGROUND: Pacemaker implantation is the most common complication following TAVR. Predictors of pacing following TAVR with the Lotus valve have not been systematically assessed. METHODS: Consecutive patients with severe aortic stenosis who underwent Lotus valve implantation were prospectively recruited at a single-centre. Patients with a pre-existing PPM were excluded. Baseline ECG, echocardiographic and multiple detector computed tomography as well as procedural telemetry and depth of implantation were independently analyzed in a blinded manner. The primary endpoint was 30-day incidence of pacemaker requirement (PPM implantation or death while pacing-dependent). Multivariate analysis was performed to identify independent predictors of the primary endpoint. RESULTS: A total of 104 consecutive patients underwent TAVR with the Lotus valve with 9/104 (9%) with a pre-existing PPM excluded. New or worsened procedural LBBB occurred in 78%. Thirty-day incidence of the primary pacing endpoint was 28%. The most common indication for PPM implantation was complete heart block (CHB) (69%). Independent predictors of the primary endpoint included pre-existing RBBB (hazard ratio [HR] 2.8, 95% CI 1.1-7.0; P = 0.032) and depth of implantation below the noncoronary cusp (NCC) (HR 2.4, 95% CI 1.0-5.7; P = 0.045). CONCLUSIONS: Almost a third of Lotus valve recipients require pacemaker implantation within 30 days. The presence of pre-existing RBBB and the depth of prosthesis implantation below the NCC were significant pacing predictors. © 2016 Wiley Periodicals, Inc.

Guideline-based intervention to reduce telemetry rates in a large tertiary centre.

BACKGROUND: Inappropriate cardiac telemetry use is associated with reduced patient flow and increased healthcare costs. AIM: To evaluate the outcomes of guideline-based application of cardiac telemetry. METHODS: Phase I involved a prospective audit (March to August 2011) of telemetry use at a tertiary hospital. Data were collected on indication for telemetry and clinical outcomes. Phase II prospectively included patients more than 18 years under general medicine requiring ward-based telemetry. As phase II occurred at a time remotely from phase I, an audit similar to phase I (phase II - baseline) was completed prior to a 3-month intervention (May to August 2015). The intervention consisted of a daily telemetry ward round and an admission form based on the American Heart Association guidelines (class I, telemetry indicated; class II, telemetry maybe indicated; class III, telemetry not indicated). Patient demographics, telemetry data, and clinical outcomes were studied. Primary endpoint was the percentage reduction of class III indications, while secondary endpoint included telemetry duration. RESULTS: In phase I (n = 200), 38% were admitted with a class III indication resulting in no change in clinical management. A total of 74 patients was included in phase II baseline (mean ± standard deviation (SD) age 73 years ± 14.9, 57% male), whilst 65 patients were included in the intervention (mean ± SD age 71 years ± 18.4, 35% male). Both groups had similar baseline characteristics. There was a reduction in class III admissions post-intervention from 38% to 11%, P < 0.001. Intervention was associated with a reduction in median telemetry duration (1.8 ± 1.8 vs 2.4 ± 2.5 days, P = 0.047); however, length of stay was similar in both groups (P > 0.05). CONCLUSION: Guideline-based telemetry admissions and a regular telemetry ward round are associated with a reduction in inappropriate telemetry use.

Retrospective Cohort Study Examining Reduced Intensity and Duration of Anticoagulant and Antiplatelet Therapy Following Left Atrial Appendage Occlusion with the WATCHMAN Device.

BACKGROUND: Anticoagulant and antiplatelet therapy are recommended following WATCHMAN implantation (45 days and 6 months) to reduce the risk of embolic events. These patients are often also at high risk of recurrent bleeding complications. We aimed to assess the safety of reduced duration of treatment with anticoagulant and antiplatelet therapy in the early post implant period. METHODS: This was a retrospective cohort study assessing the duration of antiplatelet and anticoagulant therapy in 47 consecutive patients following WATCHMAN implant. The primary outcome was rate of major bleeding, stroke and systemic embolic complications. The secondary endpoints were rate of device thrombus and peri-device leak >4mm as assessed by transoesophogeal echocardiography. RESULTS: Forty-seven patients were followed up for a mean of 2.4+/-1.7 years (111.4 total patient-years). The rate of stroke was 1.8/100 patient-years (two events) and the rate of major bleeding complication was 8.9/100 patient-years. Three patients had peri-device leak >4mm and no patients had device thrombus visualised. 70.2% of patients had discontinued anticoagulation at 45 days, 89.4% had discontinued dual antiplatelet therapy at 90 days. Seven patients were not on any form of anticoagulant or antiplatelet at five months. Comparison of probability of survival free from stroke by time of cessation of anticoagulant and antiplatelet therapy demonstrated no significant differences (p-value for log rank test 0.238 and 0.820). CONCLUSION: Following WATCHMAN implant shortened periods of anticoagulants and antiplatelets may be considered, particularly in the context of high bleeding risk.

Feasibility of exercise stress echocardiography for cardiac risk assessment in chronic kidney disease patients prior to renal transplantation.

BACKGROUND: Pharmacologic stress testing is utilized in preference to exercise stress echocardiography (ESE) for cardiac risk evaluation in potential renal transplant recipients due to the perceived lower feasibility of ESE for achieving adequate workload and target heart rate (THR) in this population. METHODS: Consecutive patients referred for cardiac risk evaluation prior to potential kidney transplantation were evaluated. All patients attempted ESE before pharmacologic testing was considered. Treadmill ESE utilized BRUCE protocol to maximum capacity. THR was defined as >85% of the maximum predicted heart rate (220-age). Functional capacity was assessed by metabolic equivalents (METs) and the rate pressure product (RPP). RESULTS: Of 535 patients (349 male, age 56±11), 372(70%) reached THR. Mean METs were 10±3 with 531(99%) achieving ≥4 METs and 87% ≥7 METs. Mean RPP was 25 821±5820 bpm×mm Hg (83% achieving >20 000 bpm×mm Hg). On multivariate analysis, independent predictors of failure to reach THR were rate-control medication and diabetes; failure to reach 7 METs: females, diabetics, age≥65, and previous cardiac disease; failure to reach RPP>20 000: rate-control medication. There were 97% of ESE completed to physiologic endpoints. CONCLUSION: In unselected potential renal transplant candidates, cardiac assessment by ESE is well tolerated, with 9-in-10 exercising to satisfactory functional capacity. ESE should be considered a feasible alternative to pharmacologic testing in this population.

Statin Therapy: Review of Safety and Potential Side Effects.

BACKGROUND: Hydroxymethyl glutaryl coenzyme A reductase inhibitors, commonly called statins, are some of the most commonly prescribed medications worldwide. Evidence suggests that statin therapy has significant mortality and morbidity benefit for both primary and secondary prevention from cardiovascular disease. Nonetheless, concern has been expressed regarding the adverse effects of long term statin use. The purpose of this article was to review the current medical literature regarding the safety of statins. METHODS: Major trials and review articles on the safety of statins were identified in a search of the MEDLINE database from 1980 to 2016, which was limited to English articles. RESULTS: Myalgia is the most common side effect of statin use, with documented rates from 1-10%. Rhabdomyolysis is the most serious adverse effect from statin use, though it occurs quite rarely (less than 0.1%). The most common risk factors for statin-related myopathy include hypothyroidism, polypharmacy and alcohol abuse. Derangement in liver function tests is common, affecting up to 1% of patients; however, the clinical significance of this is unknown. Some statin drugs are potentially diabetogenic and the risk appears to increase in those patients on higher doses. Pitavastatin has not been associated with increased risk of diabetes. Statins have not been proven to increase the risk of malignancy, dementia, mood disorders or acute interstitial nephritis. However, statins do have multiple drug interactions, primarily those which interact with the cytochrome p450 enzyme group. CONCLUSIONS: Overall, statin drugs appear to be safe for use in the vast majority of patients. However, patients with multiple medical co-morbidities are at increased risk of adverse effects from long-term statin use.

Cardiovascular Risk in Cancer Patients Treated with Immune Checkpoint Inhibitors: Challenges and Future Directions.

Cardiovascular disease is the leading cause of non-cancer related mortality and morbidity among people living with or cured from cancer. Immune checkpoint inhibitors (ICIs) are systemic anti-cancer therapies that have revolutionised the treatment of numerous cancers, even achieving durable long-term responses among patients with metastatic disease. However, the pro-inflammatory effects of ICIs have been postulated to increase the risk of atherosclerotic cardiovascular disease (ASCVD) in cancer survivorship. Standard modifiable cardiovascular risk factors can further contribute to ASCVD risk during cancer survivorship but are not routinely screened and are often untreated in patients with cancer. With the expanding use of ICIs leading to improved cancer survivorship, cardiovascular risk identification and prevention will be paramount in the care of patients with cancer. This review highlights the practical challenges associated with ASCVD prevention among the growing number of patients treated with ICIs for cancer, including balancing competing mortality risks from cancer and ASCVD, the lack of ICI-specific cardiovascular risk stratification tools, potential interactions between cardiovascular and oncological therapies, and barriers to implementation of cardiovascular screening and prevention within existing healthcare systems.

Atrial fibrillation in cancer survivors - a systematic review and meta-analysis.

BACKGROUND: Atrial fibrillation (AF) is a common cardiac complication during cancer treatment. It is unclear if cancer survivors have increased AF risk when compared to the population. AF screening is now recommended in patients ≥65 years, however there are no specific recommendations in the oncology population. We sought to compare the AF detection rate of cancer survivors compared to the general population. METHODS: We searched the Pubmed, Embase and Web of Science databases using search terms related to AF and cancer mapped to subject headings. We included English language studies, limited to adults > 18 years who were > 12 months post completion of cancer treatment. Using a random-effects model we calculated the overall AF detection rate. Meta-regression analysis was performed to assess for potential causes for study heterogeneity. RESULTS: Sixteen studies were included in the study. The combined AF detection rate amongst all the studies was 4.7% (95% C.I 4.0-5.4%), which equated to a combined annualised AF rate of 0.7% (95% C.I 0.1-0.98%). There was significant heterogeneity between studies (I2 = 99.8%, p < 0.001). In the breast cancer cohort (n = 6 studies), the combined annualised AF rate was 0.9% (95% C.I 0.1-2.3%), with significant heterogeneity (I2 = 99.9%, p < 0.001). CONCLUSION: Whilst the results should be interpreted with caution due to study heterogeneity, AF rates in patients with cancer survival >12 months were not significantly increased compared to the general population. STUDY REGISTRATION: Open Science Framework - DOI: https://doi.org/10.17605/OSF.IO/APSYG .

The importance of calibration method in determining the association between central blood pressure with left ventricular and left atrial strain.

Afterload is an important determinant of left ventricular (LV) and atrial (LA) function, including myocardial strain. Central blood pressure (CBP) is the major component of cardiac afterload and independently associated with cardiovascular risk. However, the optimal means of calibrating CBP is unclear-standard CBP assessment uses systolic (SBP) and diastolic blood pressure (DBP) from brachial waveforms, but calibration with mean pressure (MAP) and DBP purports to be more accurate. Therefore, we sought to determine which CBP is best associated with LA and LV strain. CBP was measured using both standard and MAP based calibration methods in 546 participants (age 70.7 ± 4.7 years, 45% male) with risk factors for heart failure. Echocardiography was performed in all patients and strain analysis conducted to assess LA/LV function. The associations of CBP with LA and LV strain were assessed using linear regression. MAP-derived CSBP (150 ± 20 mmHg) was higher than standard CSBP (128 ± 15 mmHg) and brachial SBP (140 ± 17 mmHg, p < 0.001), whereas DBPs were similar (84 ± 10, 83 ± 10, and 82 ± 10 mmHg). MAP-derived CSBP was not independently associated with LV strain (p > 0.05), however was independently associated with LA reservoir strain (p < 0.05). Brachial and central DBP were more strongly associated with LA reservoir/conduit and LV strain than brachial and central SBP. LA pump strain was not independently associated with any SBP or DBP parameter (p > 0.05). MAP-derived CBP was more accurate in identifying patients with abnormal LA and LV strain than brachial SBP and standard CBP calibration. In conclusion, CBP calibrated using MAP and DBP may be more accurate in identifying patients with abnormal LA and LV function than standard brachial calibration methods.

Prognostic Value of Exercise Capacity in Kidney Transplant Candidates.

Background Exercise stress testing for cardiovascular assessment in kidney transplant candidates has been shown to be a feasible alternative to pharmacologic methods. Exercise stress testing allows the additional assessment of exercise capacity, which may have prognostic value for long-term cardiovascular outcomes in pre-transplant recipients. This study aimed to evaluate the prognostic value of exercise capacity on long-term cardiovascular outcomes in kidney transplant candidates. Methods and Results We retrospectively evaluated exercise capacity in 898 consecutive kidney transplant candidates between 2013 and 2020 who underwent symptom-limited exercise stress echocardiography for pre-transplant cardiovascular assessment. Exercise capacity was measured by age- and sex-predicted metabolic equivalents (METs). The primary outcome was incident major adverse cardiovascular events, defined as cardiac death, non-fatal myocardial infarction, and stroke. Cox proportional hazard multivariable modeling was performed to define major adverse cardiovascular events predictors with transplantation treated as a time-varying covariate. A total of 429 patients (48%) achieved predicted METs. During follow-up, 93 (10%) developed major adverse cardiovascular events and 525 (58%) underwent transplantation. Achievement of predicted METs was independently associated with reduced major adverse cardiovascular events (hazard ratio [HR] 0.49; [95% CI 0.29-0.82], P=0.007), as was transplantation (HR, 0.52; [95% CI 0.30-0.91], P=0.02). Patients achieving predicted METs on pre-transplant exercise stress echocardiography had favorable outcomes that were independent (HR, 0.78; [95% CI 0.32-1.92], P=0.59) and of similar magnitude to subsequent transplantation (HR, 0.97; [95% CI 0.42-2.25], P=0.95). Conclusions Achievement of predicted METs on pre-transplant exercise stress echocardiography confers excellent prognosis independent of and of similar magnitude to subsequent kidney transplantation. Future studies should assess the benefit on exercise training in this population.

Pyopneumopericarditis from a gastropericardial fistula: a case report.

BACKGROUND: Pyopneumopericarditis is a very rare diagnosis that requires prompt recognition and urgent treatment. It denotes the presence of pus and air in the pericardium with associated inflammation of the fibrous pericardial sac. CASE SUMMARY: A 49-year-old gentleman was admitted with pyopneumoperciarditis on a background of a previous uncomplicated Roux-en-Y gastric bypass surgery performed 7 years prior. He underwent emergency surgery for an omental patch repair of an ulcer perforation involving the diaphragm and pericardium. His inpatient stay was complicated by persistent seropurulent output from the pericardial drain, loculated pleural effusion, and deconditioning. DISCUSSION: Management is extrapolated from the literature regarding purulent pericarditis. This condition albeit rare, requires swift recognition as without treatment mortality approaches 100%. Colchicine is an important adjunctive therapy postoperatively to prevent constrictive physiology.

Associations of subclinical heart failure and atrial fibrillation with mild cognitive impairment: a cross-sectional study in a subclinical heart failure screening programme.

OBJECTIVES: Effective identification and management of subclinical left ventricular (LV) dysfunction (LVD) and subclinical atrial fibrillation (AF) by screening elderly populations might be compromised by mild cognitive impairment (MCI). We sought to characterise the prevalence and profile of MCI and evaluate associations with LV and left atrial (LA) dysfunction and AF, in a trial of screening for subclinical LVD and AF. DESIGN: Cross-sectional. SETTING: Australian, community-based intervention trial. PARTICIPANTS: Adults aged ≥65 years with ≥1 LVD risk factors without ischaemic heart disease (n=337). OUTCOME MEASURES: The Montreal cognitive assessment (MoCA) was obtained. Subclinical LVD was defined as echocardiographic global longitudinal strain ≤16%, diastolic dysfunction or LV hypertrophy; abnormal LA reservoir strain (LARS) was defined as <24%. Subclinical AF was detected using a single-lead portable electrocardiographic device in those without pre-existing AF who gave consent (n=293). RESULTS: Subclinical LVD was found in 155 (46%), abnormal LARS in 9 (3.6%) and subclinical AF in 11 (3.8%). MoCA score consistent with MCI (<26) was found in 101 (30%); executive function (69%) and delayed recall (93%), were the most frequently abnormal domains. Compared with normal cognition, MCI was associated with non-adherence to AF screening (25% vs 40%, p=0.01). In multivariable logistic regression modelling, educational achievement, systolic blood pressure, body mass index and waist-to-hip ratio were independently associated with MCI. However, neither subclinical AF nor any measure of cardiac dysfunction, were associated with MCI. CONCLUSIONS: The 30% prevalence of MCI among elderly subjects with risk factors for subclinical LVD and AF has important implications for screening strategies and management. However, MCI is not associated with subclinical myocardial dysfunction nor subclinical AF. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12617000116325).

Impact of disease stage on the performance of strain markers in the prediction of atrial fibrillation.

BACKGROUND: Assessing atrial fibrillation (AF) risk may be useful in primary prevention (PP; people with risk factors) and secondary prevention (SP; eg. embolic stroke of unknown source). We sought whether disease stage influenced the prediction of AF by echocardiography. METHODS: We compared a PP cohort (351 community-based participants ≥65 years with ≥1 risk factor for AF) and a SP cohort (453 patients after transient ischemic attack or stroke). LV global longitudinal strain (GLS) and left atrial reservoir strain (LARS) were measured from DICOM images. AF was diagnosed by 12 lead ECG, Holter or by single lead monitor over median follow-up of 22 months (PP) and 35 months (SP). The clinical and echocardiographic characteristics of those with AF were compared to those in sinus rhythm. Nested Cox-regression models assessed for independent and incremental predictive value of LARS and GLS in both cohorts. RESULTS: AF developed in 42 PP (12%) and 60 SP (13%), and was associated with age, higher CHARGE-AF score, increased LA volume and LV mass (p < 0.05). Patients developing AF had reduced GLS (17 ± 3.5% vs. 20 ± 3%, p < 0.001) and LARS (28 ± 11% vs. 35 ± 8%, p < 0.001). However, the predictive value of both GLS (area under the ROC curve 0.83 vs 0.56, p < 0.001) and LARS (0.83 vs 0.57, p < 0.001) was greater in SP than PP. LARS was independently associated with AF in both cohorts (p < 0.05), but GLS was only independently associated in the SP cohort. CONCLUSION: AF risk assessment with LARS is suitable for different risk cohorts, but GLS is more useful in SP.

Coronary artery ectasia presenting with ST-elevation myocardial infarction in a young indigenous man: a case report.

BACKGROUND: Coronary artery ectasia (CAE) is often an incidental finding on angiography, however, patients can present with acute coronary syndrome due to a large thrombus burden requiring treatment with percutaneous coronary intervention or with emergency surgery. CASE SUMMARY: A 26-year-old Indigenous Australian male was admitted with anterior ST-elevation myocardial infarction associated with an out of hospital ventricular fibrillation arrest. Coronary angiography demonstrated thrombotic occlusion of the proximal left anterior descending (LAD) artery with heavy thrombus burden and prominent vascular ectasia of all three coronary arteries. He was managed with surgical thrombectomy and coronary artery bypass graft of his LAD. DISCUSSION: This is the first case of triple CAE in an Indigenous Australian. The case highlights the lack of consensus approach in the management of CAE due to paucity of prospective studies.

Use of echocardiography to stratify the risk of atrial fibrillation: comparison of left atrial and ventricular strain.

AIMS: Although both left atrial (LA) and ventricular (LV) dysfunction has been accepted as an important risk factor of atrial fibrillation (AF), usefulness of LA and LV strain has not been fully compared for prediction of AF. The aims of this study were to clarify the associations of both LA and LV strain with AF and to compare their predictive values in the risk stratification for AF. METHODS AND RESULTS: We evaluated 531 consecutive patients (median age 67 years, 56% male), with no history of AF who underwent echocardiography after cryptogenic stroke. Standard echocardiographic parameters were measured, and speckle-tracking was used to measure LA (reservoir, pump, and conduit strain) and LV strain (global longitudinal strain, GLS). The baseline clinical and echocardiographic parameters of the patients who developed AF and those who did not were compared. Median 36 months of follow-up, 61 patients (11%) had newly diagnosed AF. LA pump strain and GLS were significantly and independently associated with AF and provided incremental predictive value over clinical and standard echocardiographic parameters. Areas under the receiver-operating curves for GLS (0.841) were comparable to LA pump (0.825) and reservoir (0.851) strain. However, predictive value of both strains was different between patients with and without LA enlargement at the time of transthoracic echocardiography screening. LA strain was more useful than LV strain in patients with normal LA volumes, while LV strain was more useful than LA strain in patients with abnormal LA volumes. CONCLUSION: Both LA and LV strain are significantly and independently associated with AF and provide incremental predictive value over clinical and standard echocardiographic parameters. However, priorities of strain assessment are different depends on patients' condition at the time of echocardiography.

Association of Asymptomatic Diastolic Dysfunction Assessed by Left Atrial Strain With Incident Heart Failure.

OBJECTIVES: This study is to establish the association of left atrial reservoir strain (LARS) with incident heart failure (HF), and the impact of substituting LARS for left atrial (LA) volume index (LAVI) in diastolic assessment. BACKGROUND: LARS measures passive LA stretch and is a sensitive marker of left ventricular diastolic dysfunction (DD). The potential contribution of LARS to diastolic assessment is unclear. METHODS: Baseline clinical and echocardiographic assessments were obtained in 758 asymptomatic, community-dwelling elderly subjects (age 70 [interquartile range: 67 to 74] years, 53% women) with nonischemic HF risk factors. LARS-defined DD (LARS-DD) was assessed by speckle-tracking echocardiography, and grades were assigned as normal (>35%), grade 1 (25% to 35%) and grade 2 (≤24%). DD grade using current recommendations was compared with grading using LARS <24% in place of LAVI >34 ml/m2. Patients were followed for up to 2 years for incident HF. RESULTS: LA strain analysis was feasible in 738 (97%) patients; average LARS was 39% (range 34% to 43%). Incident HF was associated with LARS-DD grade; 8 (36%) of those had grade 2+, 14 (10%) had grade 1, and 39 (9%) had normal function (p < 0.001). LARS-DD grade 2+ predicted incident HF after adjustment for clinical and echocardiographic markers (adjusted hazard ratio: 2.5; 95% confidence interval: 1.02 to 6.3; p = 0.049); there was no significant HF risk associated with LARS-DD grade 1. Dichotomized abnormal LARS <24% had an adjusted hazard ratio of 2.9 (95% confidence interval: 1.25 to 6.79; p = 0.013). Substituting LARS for LAVI provided a 75% reduction in indeterminate diastolic function; all were recategorized as normal. There was no increased risk associated normal diastolic function by this grading compared to conventional grading (C-statistic = 0.76 for both models). CONCLUSIONS: LARS-DD grade 2+ is associated with incident HF in the elderly, independent of LAVI. The substitution of LARS for LAVI reduces the number of indeterminate cases without impacting prognosis in normal diastolic function and grade 1 DD.

Left Atrial Mechanical Dispersion Assessed by Strain Echocardiography as an Independent Predictor of New-Onset Atrial Fibrillation: A Case-Control Study.

BACKGROUND: Left atrial (LA) enlargement is associated with atrial fibrillation (AF), but new-onset AF often occurs in the absence of LA enlargement. AF may be related to myocardial fibrosis, and even though left ventricular fibrosis is associated with mechanical dispersion, this phenomenon is not well studied in AF. We hypothesized that detection of LA dysfunction and mechanical dispersion using strain echocardiography is useful for predicting new-onset AF. METHODS: Baseline echocardiography was performed at entry in 576 community-based participants at risk of heart failure or AF. In this case-control study, we compared 35 individuals with new-onset AF (age 70 ± 4 years; 57% men) over 2 years of follow-up with 35 age- and sex-matched individuals who did not develop AF from the same cohort. Using speckle-tracking echocardiography, we measured the LA strain in each of 12 segments in the two- and four-chamber views. LA mechanical dispersion was defined as the SD of time to peak positive strain corrected by the R-R interval (SD-TPS, %). RESULTS: There was no significant difference in LA volume index (32.5 ± 9.2 mL/m2 vs 29.5 ± 8.3 mL/m2; P = .16); patients with new-onset AF had significantly worse LA pump strain (16.6% ± 4.3% vs 20.6% ± 4.3%; P < .01) and reservoir strain (31.4% ± 7.7% vs 38.0% ± 7.3%; P < .01) than those without AF. SD-TPS was significantly higher in patients with AF than in those without it (6.3% ± 2.3% vs 3.9% ± 1.6%; P < .01). SD-TPS was independently associated with new-onset AF after adjustment for patient characteristics, LA volume, and strain (hazard ratio = 1.26; 95% CI, 1.10-1.45; P < .01). In the nested Cox models, the model based on the LA volume and strain for predicting new onset AF was significantly improved by adding SD-TPS (P < .01). CONCLUSIONS: LA dispersion obtained from strain echocardiography seems to provide incremental information about LA volume and function in the prediction of new-onset AF and warrants testing in a larger study.