Skeletal Muscle Disorders: A Noncardiac Source of Cardiac Troponin T.

BACKGROUND: Cardiac troponin (cTn) T and cTnI are considered cardiac specific and equivalent in the diagnosis of acute myocardial infarction. Previous studies suggested rare skeletal myopathies as a noncardiac source of cTnT. We aimed to confirm the reliability/cardiac specificity of cTnT in patients with various skeletal muscle disorders (SMDs). METHODS: We prospectively enrolled patients presenting with muscular complaints (≥2 weeks) for elective evaluation in 4 hospitals in 2 countries. After a cardiac workup, patients were adjudicated into 3 predefined cardiac disease categories. Concentrations of cTnT/I and resulting cTnT/I mismatches were assessed with high-sensitivity (hs-) cTnT (hs-cTnT-Elecsys) and 3 hs-cTnI assays (hs-cTnI-Architect, hs-cTnI-Access, hs-cTnI-Vista) and compared with those of control subjects without SMD presenting with adjudicated noncardiac chest pain to the emergency department (n=3508; mean age, 55 years; 37% female). In patients with available skeletal muscle biopsies, TNNT/I1-3 mRNA differential gene expression was compared with biopsies obtained in control subjects without SMD. RESULTS: Among 211 patients (mean age, 57 years; 42% female), 108 (51%) were adjudicated to having no cardiac disease, 44 (21%) to having mild disease, and 59 (28%) to having severe cardiac disease. hs-cTnT/I concentrations significantly increased from patients with no to those with mild and severe cardiac disease for all assays (all P<0.001). hs-cTnT-Elecsys concentrations were significantly higher in patients with SMD versus control subjects (median, 16 ng/L [interquartile range (IQR), 7-32.5 ng/L] versus 5 ng/L [IQR, 3-9 ng/L]; P<0.001), whereas hs-cTnI concentrations were mostly similar (hs-cTnI-Architect, 2.5 ng/L [IQR, 1.2-6.2 ng/L] versus 2.9 ng/L [IQR, 1.8-5.0 ng/L]; hs-cTnI-Access, 3.3 ng/L [IQR, 2.4-6.1 ng/L] versus 2.7 ng/L [IQR, 1.6-5.0 ng/L]; and hs-cTnI-Vista, 7.4 ng/L [IQR, 5.2-13.4 ng/L] versus 7.5 ng/L [IQR, 6-10 ng/L]). hs-cTnT-Elecsys concentrations were above the upper limit of normal in 55% of patients with SMD versus 13% of control subjects (P<0.01). mRNA analyses in skeletal muscle biopsies (n=33), mostly (n=24) from individuals with noninflammatory myopathy and myositis, showed 8-fold upregulation of TNNT2, encoding cTnT (but none for TNNI3, encoding cTnI) versus control subjects (n=16, PWald<0.001); the expression correlated with pathological disease activity (R=0.59, Pt-statistic<0.001) and circulating hs-cTnT concentrations (R=0.26, Pt-statistic=0.031). CONCLUSIONS: In patients with active chronic SMD, elevations in cTnT concentrations are common and not attributable to cardiac disease in the majority. This was not observed for cTnI and may be explained in part by re-expression of cTnT in skeletal muscle. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03660969.

Coronary artery calcium score and pre-test probabilities as gatekeepers to predict and rule out perfusion defects in positron emission tomography.

BACKGROUND: Little is known about the gatekeeper performance of coronary artery calcium score (CACS) before myocardial perfusion positron emission tomography (PET), compared with updated pre-test probabilities from American and European guidelines (pre-test-AHA/ACC, pre-test-ESC). METHODS: We enrolled participants without known coronary artery disease undergoing CACS and Rubidium-82 PET. Abnormal perfusion was defined as summed stress score ≥ 4. Using Bayes' formula, pre-test probabilities and CACS were combined into post-test probabilities. RESULTS: We included 2050 participants (54% male, mean age 64.6 years) with median CACS 62 (IQR 0-380), pre-test-ESC 17% (11-26), pre-test-AHA/ACC 27% (16-44), and abnormal perfusion in 437 participants (21%). To predict abnormal perfusion, area under the curve of CACS was 0.81, pre-test-AHA/ACC 0.68, pre-test-ESC 0.69, post-test-AHA/ACC 0.80, and post-test-ESC 0.81 (P < 0.001 for CACS vs. each pre-test, and each post-test vs. pre-test). CACS = 0 had 97% negative predictive value (NPV), pre-test-AHA/ACC ≤ 5% 100%, pre-test-ESC ≤ 5% 98%, post-test-AHA/ACC ≤ 5% 98%, and post-test-ESC ≤ 5% 96%. Among participants, 26% had CACS = 0, 2% pre-test-AHA/ACC ≤ 5%, 7% pre-test-ESC ≤ 5%, 23% post-test-AHA/ACC ≤ 5%, and 33% post-test-ESC ≤ 5% (all P < 0.001). CONCLUSIONS: CACS and post-test probabilities are excellent predictors of abnormal perfusion and can rule it out with very high NPV in a substantial proportion of participants. CACS and post-test probabilities may be used as gatekeepers before advanced imaging. Coronary artery calcium score (CACS) predicted abnormal perfusion (SSS ≥ 4) in myocardial positron emission tomography (PET) better than pre-test probabilities of coronary artery disease (CAD), while pre-test-AHA/ACC and pre-test-ESC performed similarly (left). Using Bayes' formula, pre-test-AHA/ACC or pre-test-ESC were combined with CACS into post-test probabilities (middle). This calculation reclassified a substantial proportion of participants to low probability of CAD (0-5%), not needing further imaging, as shown for AHA/ACC probabilities (2% with pre-test-AHA/ACC to 23% with post-test-AHA/ACC, P < 0.001, right). Very few participants with abnormal perfusion were classified under pre-test or post-test probabilities 0-5%, or under CACS 0. AUC: area under the curve. Pre-test-AHA/ACC: Pre-test probability of the American Heart Association/American College of Cardiology. Post-test-AHA/ACC: Post-test probability combining pre-test-AHA/ACC and CACS. Pre-test-ESC: Pre-test probability of the European Society of Cardiology. SSS: Summed stress score.

The power of zero calcium in 82-Rubidium PET irrespective of sex and age.

BACKGROUND: Despite clinical suspicion, many non-invasive tests for coronary artery disease (CAD) are normal. Coronary artery calcification score (CACS) is a well-validated method to detect and risk stratify CAD. Patients with zero calcium score (ZCS) rarely have abnormal tests. Therefore, aims were to evaluate CACS as a gatekeeper to further functional downstream testing for CAD and estimate potential radiation and cost savings. METHODS: Consecutive patients with suspected CAD referred for PET were included (n = 2640). Prevalence and test characteristics of ZCS were calculated in different groups. Summed stress score ≥ 4 was considered abnormal and summed difference score ≥ 7 equivalent to ≥ 10% ischemia. To estimate potential radiation/cost reduction, PET scans were hypothetically omitted in ZCS patients. RESULTS: Mean age was 65 ± 11 years, 46% were female. 21% scans were abnormal and 26% of patients had ZCS. CACS was higher in abnormal PET (median 561 vs 27, P < 0.001). Abnormal PET was significantly less frequent in ZCS patients (2.6% vs 27.6%, P < 0.001). Sensitivity/negative predictive value (NPV) of ZCS to detect/exclude abnormal PET and ≥ 10% ischemia were 96.8% (95%-CI 95.0%-97.9%)/97.4% (95.9%-98.3%) and 98.9% (96.7%-99.6%)/99.6% (98.7%-99.9%), respectively. Radiation and cost reduction were estimated to be 23% and 22%, respectively. CONCLUSIONS: ZCS is frequent, and most often consistent with normal PET scans. ZCS offers an excellent NPV to exclude an abnormal PET and ≥ 10% ischemia across different gender and age groups. CACS is a suitable gatekeeper before advanced cardiac imaging, and potential radiation/cost savings are substantial. However, further studies including safety endpoints are needed.

Low-dose coronary artery calcium scoring compared to the standard protocol.

BACKGROUND: We aimed to compare coronary artery calcium scoring (CACS) with computed tomography (CT) with 80 and 120 kVp in a large patient population and to establish whether there is a difference in risk classification between the two scores. METHODS: Patients with suspected CAD undergoing MPS were included. All underwent standard CACS assessment with 120-kVp tube voltage and with 80 kVp. Two datasets (low-dose and standard) were generated and compared. Risk classes (0 to 25, 25 to 50, 50 to 75, 75 to 90, and > 90%) were recorded. RESULTS: 1511 patients were included (793 males, age 69 ± 9.1 years). There was a very good correlation between scores calculated with 120 and 80 kVp (R = 0.94, R2 = 0.88, P < .001), with Bland-Altman limits of agreement of - 563.5 to 871.9 and a bias of - 154.2. The proportion of patients assigned to the < 25% percentile class (P = .03) and with CACS = 0 differed between the two protocols (n = 264 vs 437, P < .001). CONCLUSION: In a large patient population, despite a good correlation between CACS calculated with standard and low-dose CT, there is a systematic underestimation of CACS with the low-dose protocol. This may have an impact especially on the prognostic value of the calcium score, and the established "power of zero" may no longer be warranted if CACS is assessed with low-dose CT.

Quantitative myocardial perfusion 82Rb-PET assessed by hybrid PET/coronary-CT: Normal values and diagnostic performance.

PURPOSE: We aimed to assess normal values for quantified myocardial blood flow (MBF) on a hybrid PET/coronary-CT scanner and to test their diagnostic performance in patients with suspected CAD. MATERIALS AND METHODS: Patients underwent 82Rb-PET/CT and integrated CT-based coronary angiography (CCTA) and were classified as normal (no stenosis), with non-obstructive stenosis (< 50%) and with CAD (≥ 50%). Global and regional stress MBF (sMBF), rest MBF and myocardial flow reserve (MFR) were calculated. Ischemia was defined as SDS ≥ 2, severe ischemia as SDS ≥ 7. RESULTS: 357 consecutive patients were included. Global sMBF and MFR were higher in normal patients than in patients with CAD (3.61 ± 0.71 vs 3.04 ± 0.77, P < 0.0001; 3.08 ± 0.84 vs 2.68 ± 0.79, P = 0.0001), but not different compared to patients with non-obstructive stenosis (3.61 ± 0.71 vs 3.43 ± 0.69, P = 0.052; 3.08 ± 0.84 vs 2.99 ± 0.82, P = 0.45). sMBF yielded superior accuracy over MFR in identifying both ischemia (AUC 0.74 vs 0.62, P = 0.003) and severe ischemia (AUC 0.88 vs 0.78, P = 0.012). Optimal threshold for global sMBF to rule out myocardial ischemia was 3.5 mL g-1 min-1. CONCLUSIONS: Normal quantitative values are provided. Global sMBF provided higher diagnostic accuracy than MFR. Using sMBF-threshold of 3.5 mL·g-1·min-1 on 82Rb-PET/CT yielded similar NPV (96%) as CCTA to rule out CAD. Hence, resting scan could be omitted in patients with sMBF values above reference.

Left ventricular ejection fraction, myocardial blood flow and hemodynamic variables in adenosine and regadenoson vasodilator 82-Rubidium PET.

AIMS: In most Rubidium-(Rb)-positron emission tomography (PET) studies, dipyridamole was used as vasodilator. The aim was to evaluate vasodilator PET left ventricular ejection fraction (LVEF), myocardial blood flow (MBF), hemodynamics, and the influence of adenosine and regadenoson on these variables. METHODS AND RESULTS: Consecutive patients (N = 2299) with prior coronary artery disease (CAD) or no prior CAD undergoing adenosine/regadenoson 82Rb-PET were studied and compared according to CAD status and normal/abnormal PET (summed stress score 0-3 vs. ≥4). Rest and stress LVEF differed significantly depending on CAD status and scan results. In patients with no prior CAD, rest/stress LVEF were 68% and 72%, in patients with prior CAD 60% and 63%. LVEF during stress increased 5 ± 6% in normal compared to 1 ± 8% in abnormal PET (P<0.001). Global rest myocardial blood flow(rMBF), stress MBF(sMBF) and myocardial flow reserve (sMBF/rMBF) were significantly higher in no prior CAD patients compared to prior CAD patients(1.3 ± 0.5, 3.3 ± 0.9, 2.6 ± 0.8 and 1.2 ± 0.4, 2.6 ± 0.8, 2.4 ± 0.8 ml/g/min, respectively, P<0.001) and in normal versus abnormal scans, irrespective of CAD status(no prior CAD: 1.4 ± 0.5, 3.5 ± 0.8, 2.8 ± 0.8 and 1.2 ± 0.8, 2.5 ± 0.8, 2.2 ± 0.7; prior CAD: 1.3 ± 0.4, 3.1 ± 0.8, 2.7 ± 0.8 and 1.1 ± 0.4, 2.3 ± 0.7, 2.2 ± 0.7 ml/g/min, respectively, P<0.001). LVEF and hemodynamic values were similar for adenosine and regadenoson stress. Stress LVEF ≥70% excluded relevant ischemia (≥10%) with a negative predictive value (NPV) of 94% (CI 92-95%). CONCLUSIONS: Rest/stress LVEF, LVEF reserve and MBF values are lower in abnormal compared to normal scans. Adenosine and regadenoson seem to have similar effect on stress LVEF, MBF and hemodynamics. A stress LVEF ≥70% has a high NPV to exclude relevant ischemia.

Prognostic value of myocardial perfusion scintigraphy in asymptomatic patients with diabetes mellitus at high cardiovascular risk: 5-year follow-up of the prospective multicenter BARDOT trial.

BACKGROUND: The Basel Asymptomatic High-Risk Diabetics' Outcome Trial (BARDOT) demonstrated that asymptomatic diabetic patients with an abnormal myocardial perfusion scintigraphy (MPS) were at increased risk of major adverse cardiovascular events (MACEs) at 2-year follow-up. It remains unclear whether this finding holds true even for a longer follow-up. METHODS: Four hundred patients with type 2 diabetes, neither history nor symptoms of coronary artery disease (CAD), were evaluated clinically and with MPS. Patients were followed up for 5 years. Major adverse cardiovascular events (MACEs) were defined as all-cause death, myocardial infarction, or late coronary revascularization. RESULTS: At baseline, an abnormal MPS (SSS ≥ 4 or SDS ≥ 2) was found in 87 of 400 patients (22%). MACE within 5 years occurred in 14 patients with abnormal MPS (16.1%) and in 22 with normal scan (1.7%), p = 0.009; 15 deaths were recorded. Patients with completely normal MPS (SSS and SDS = 0) had lower rates of MACEs than patients with abnormal scans (2.5% vs. 7.0%, p = 0.032). Patients with abnormal MPS who had undergone revascularization had a lower mortality rate and a better event-free survival from MI and revascularization than patients with abnormal MPS who had either undergone medical therapy only or could not be revascularized (p = 0.002). CONCLUSIONS: MPS may have prognostic value in asymptomatic diabetic patients at high cardiovascular risk over a follow-up period of 5 years. Patients with completely normal MPS have a low event rate and may not need retesting within 5 years. Patients with an abnormal MPS have higher event rates and may benefit from a combined medical and revascularization approach.

Atri-U: assisted image analysis in routine cardiovascular magnetic resonance volumetry of the left atrium.

BACKGROUND: Artificial intelligence can assist in cardiac image interpretation. Here, we achieved a substantial reduction in time required to read a cardiovascular magnetic resonance (CMR) study to estimate left atrial volume without compromising accuracy or reliability. Rather than deploying a fully automatic black-box, we propose to incorporate the automated LA volumetry into a human-centric interactive image-analysis process. METHODS AND RESULTS: Atri-U, an automated data analysis pipeline for long-axis cardiac cine images, computes the atrial volume by: (i) detecting the end-systolic frame, (ii) outlining the endocardial borders of the LA, (iii) localizing the mitral annular hinge points and constructing the longitudinal atrial diameters, equivalent to the usual workup done by clinicians. In every step human interaction is possible, such that the results provided by the algorithm can be accepted, corrected, or re-done from scratch. Atri-U was trained and evaluated retrospectively on a sample of 300 patients and then applied to a consecutive clinical sample of 150 patients with various heart conditions. The agreement of the indexed LA volume between Atri-U and two experts was similar to the inter-rater agreement between clinicians (average overestimation of 0.8 mL/m2 with upper and lower limits of agreement of - 7.5 and 5.8 mL/m2, respectively). An expert cardiologist blinded to the origin of the annotations rated the outputs produced by Atri-U as acceptable in 97% of cases for step (i), 94% for step (ii) and 95% for step (iii), which was slightly lower than the acceptance rate of the outputs produced by a human expert radiologist in the same cases (92%, 100% and 100%, respectively). The assistance of Atri-U lead to an expected reduction in reading time of 66%-from 105 to 34 s, in our in-house clinical setting. CONCLUSIONS: Our proposal enables automated calculation of the maximum LA volume approaching human accuracy and precision. The optional user interaction is possible at each processing step. As such, the assisted process sped up the routine CMR workflow by providing accurate, precise, and validated measurement results.

Quantitative 99mTc-DPD SPECT/CT in patients with suspected ATTR cardiac amyloidosis: Feasibility and correlation with visual scores.

PURPOSE: While a visual interpretation of 99mTc-DPD scintigraphy by means of Perugini score can provide a reliable diagnosis of transthyretin-related (ATTR) cardiac amyloidosis (CA), a quantitative approach is expected to play a major role in risk stratification and therapy evaluation. The aim of our study was to test the feasibility of a quantitative assessment and to correlate various parameters to Perugini score. METHODS: in this retrospective study, consecutive patients underwent a 99mTc-DPD whole-body bone scintigraphy and a SPECT/CT of the thorax. XSPECT-QUANT software was used to quantify the DPD uptake in the heart. RESULTS: Thirteen patients were included. CA was confirmed in 8 and rejected in 5. Myocardial SUVmax and SUVpeak showed a fairly strong correlation with Perugini score (both ρ = .71, P = .006). Same held true for to-bone normalized values (both ρ = .75, P = .003). There was a great degree of overlap for quantitative values in patients with Perugini score 2 and 3. CONCLUSION: Quantitative 99mTc-DPD SPECT/CT in suspected ATTR CA patients is feasible and allows for a more accurate assessment of myocardial uptake.

Inflammatory Biomarkers and Clinical Judgment in the Emergency Diagnosis of Urgent Abdominal Pain.

BACKGROUND: The early diagnosis of urgent abdominal pain (UAP) is challenging. Most causes of UAP are associated with extensive inflammation. Therefore, we hypothesized that quantifying inflammation using interleukin-6 and/or procalcitonin would provide incremental value in the emergency diagnosis of UAP. METHODS: This was an investigator-initiated prospective, multicenter diagnostic study enrolling patients presenting to the emergency department (ED) with acute abdominal pain. Clinical judgment of the treating physician regarding the presence of UAP was quantified using a visual analog scale after initial clinical and physician-directed laboratory assessment, and again after imaging. Two independent specialists adjudicated the final diagnosis and the classification as UAP (life-threatening, needing urgent surgery and/or hospitalization for acute medical reasons) using all information including histology and follow-up. Interleukin-6 and procalcitonin were measured blinded in a central laboratory. RESULTS: UAP was adjudicated in 376 of 1038 (36%) patients. Diagnostic accuracy for UAP was higher for interleukin-6 [area under the ROC curve (AUC), 0.80; 95% CI, 0.77-0.82] vs procalcitonin (AUC, 0.65; 95% CI, 0.62-0.68) and clinical judgment (AUC, 0.69; 95% CI, 0.65-0.72; both P < 0.001). Combined assessment of interleukin-6 and clinical judgment increased the AUC at presentation to 0.83 (95% CI, 0.80-0.85) and after imaging to 0.87 (95% CI, 0.84-0.89) and improved the correct identification of patients with and without UAP (net improvement in mean predicted probability: presentation, +19%; after imaging, +15%; P < 0.001). Decision curve analysis documented incremental value across the full range of pretest probabilities. A clinical judgment/interleukin-6 algorithm ruled out UAP with a sensitivity of 97% and ruled in UAP with a specificity of 93%. CONCLUSIONS: Interleukin-6 significantly improves the early diagnosis of UAP in the ED.

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.

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.

Extra-cellular expansion in the normal, non-infarcted myocardium is associated with worsening of regional myocardial function after acute myocardial infarction.

BACKGROUND: Expansion of the myocardial extracellular volume (ECV) is a surrogate measure of focal/diffuse fibrosis and is an independent marker of prognosis in chronic heart disease. Changes in ECV may also occur after myocardial infarction, acutely because of oedema and in convalescence as part of ventricular remodelling. The objective of this study was to investigate changes in the pattern of distribution of regional (normal, infarcted and oedematous segments) and global left ventricular (LV) ECV using semi-automated methods early and late after reperfused ST-elevation myocardial infarction (STEMI). METHODS: Fifty patients underwent cardiovascular magnetic resonance (CMR) imaging acutely (24 h-72 h) and at convalescence (3 months). The CMR protocol included: cines, T2-weighted (T2 W) imaging, pre-/post-contrast T1-maps and LGE-imaging. Using T2 W and LGE imaging on acute scans, 16-segments of the LV were categorised as normal, oedema and infarct. 800 segments (16 per-patient) were analysed for changes in ECV and wall thickening (WT). RESULTS: From the acute studies, 325 (40.6%) segments were classified as normal, 246 (30.8%) segments as oedema and 229 (28.6%) segments as infarct. Segmental change in ECV between acute and follow-up studies (Δ ECV) was significantly different for normal, oedema and infarct segments (0.8 ± 6.5%, -1.78 ± 9%, -2.9 ± 10.9%, respectively; P < 0.001). Normal segments which demonstrated deterioration in wall thickening at follow-up showed significantly increased Δ ECV compared with normal segments with preserved wall thickening at follow up (1.82 ± 6.05% versus -0.10 ± 6.88%, P < 0.05). CONCLUSION: Following reperfused STEMI, normal myocardium demonstrates subtle expansion of the extracellular volume at 3-month follow up. Segmental ECV expansion of normal myocardium is associated with worsening of contractile function.

Quality of life as predictor for the development of cardiac ischemia in high-risk asymptomatic diabetic patients.

BACKGROUND: Ischemia induced by psychological stress and depression is a common phenomenon in stable coronary artery disease (CAD). We evaluated the quality of life (QoL) of diabetic patients screened for CAD and assessed the prognostic value of mental and physical QoL scores to predict the development of new cardiac ischemia. METHODS: Prospective multicentre outcome study. The study comprised 400 asymptomatic diabetic patients without history or symptoms of CAD. They underwent myocardial perfusion single-photon emission computed tomography (MPS) and assessment of QoL by two questionnaires: Hospital Depression and Anxiety Scale (HADS-D and HADS-A) and Medical Outcomes Study Short Form 36 (SF-36) at baseline and after 2 years. Patients with normal MPS received usual care; those with abnormal MPS received medical or combined invasive and medical management. RESULTS: Only mental QoL scores but not physical QoL scores or traditional cardiovascular risk factors were predictive of new ischemia (n = 11/306) during follow-up. The prognostic value for new ischemia as quantified by the area under the receiver operating characteristics curve (AUC) amounted to 0.784 (95% confidence interval (CI) 0.654-0.914, P = 0.002) for HADS-D and to 0.737 (95% CI 0.580-0.893, P = 0.011) for HADS-A. This finding was confirmed by SF-36 mental sum score (AUC 0.688, 95% CI 0.539-0.836, P = 0.036), but not SF-36 physical sum score. QoL scores did not change after 2 years in patients with ischemia at baseline. CONCLUSIONS: QoL scores assessing mental health, particularly depression and anxiety, predicted the development of new cardiac ischemia in asymptomatic diabetic patients. The study is limited by a small number of events (new ischemia) and so the results should be considered hypothesis generating rather than conclusive.

Misdiagnosis of Myocardial Infarction Related to Limitations of the Current Regulatory Approach to Define Clinical Decision Values for Cardiac Troponin.

BACKGROUND: Misdiagnosis of acute myocardial infarction (AMI) may significantly harm patients and may result from inappropriate clinical decision values (CDVs) for cardiac troponin (cTn) owing to limitations in the current regulatory process. METHODS AND RESULTS: In an international, prospective, multicenter study, we quantified the incidence of inconsistencies in the diagnosis of AMI using fully characterized and clinically available high-sensitivity (hs) cTn assays (hs-cTnI, Abbott; hs-cTnT, Roche) among 2300 consecutive patients with suspected AMI. We hypothesized that the approved CDVs for the 2 assays are not biologically equivalent and might therefore contribute to inconsistencies in the diagnosis of AMI. Findings were validated by use of sex-specific CDVs and parallel measurements of other hs-cTnI assays. AMI was the adjudicated diagnosis in 473 patients (21%). Among these, 86 patients (18.2%) had inconsistent diagnoses when the approved uniform CDV was used. When sex-specific CDVs were used, 14.1% of female and 22.7% of male AMI patients had inconsistent diagnoses. Using biologically equivalent CDV reduced inconsistencies to 10% (P<0.001). These findings were confirmed with parallel measurements of other hs-cTn assays. The incidence of inconsistencies was only 7.0% for assays with CDVs that were nearly biologically equivalent. Patients with inconsistent AMI had long-term mortality comparable to that of patients with consistent diagnoses (P=NS) and a trend toward higher long-term mortality than patients diagnosed with unstable angina (P=0.05). CONCLUSIONS: Currently approved CDVs are not biologically equivalent and contribute to major inconsistencies in the diagnosis of AMI. One of 5 AMI patients will receive a diagnosis other than AMI if managed with the alternative hs-cTn assay. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00470587.

Safety and efficacy of the 0 h/3 h protocol for rapid rule out of myocardial infarction.

BACKGROUND: The early and accurate diagnosis of acute myocardial infarction (AMI) is an important medical and economic challenge. We aimed to prospectively evaluate the performance of the new European Society of Cardiology rapid 0-hour/3-hour (0 h/3 h) rule out protocol for AMI. METHODS: We enrolled 2,727 consecutive patients presenting with suspected AMI without persistent ST-segment elevation to the emergency department in a prospective international multicenter study. The final diagnosis was adjudicated by 2 independent cardiologists. The performance of the 0 h/3 h rule out protocol was evaluated using 4 high-sensitivity (primary analysis) and 3 sensitive cardiac troponin (cTn) assays. RESULTS: Acute myocardial infarction was the final diagnosis in 473 patients (17.3%). Using the 4 high-sensitivity cTn assays, the 0-hour rule out protocol correctly ruled out 99.8% (95% [confidence interval] CI, 98.7%-100%), 99.6% (95% CI, 98.5%-99.9%), 100% (95% CI, 97.9%-100%), and 100% (95% CI, 98.0%-100%) of late presenters (>6 h from chest pain onset). The 3-hour rule out protocol correctly ruled out 99.9% (95% CI, 99.1%-100%), 99.5% (95% CI, 98.3%-99.9%), 100% (95% CI, 98.1%-100%), and 100% (95% CI, 98.2%-100%) of early presenters (<6 h from chest pain onset). Using the 3 sensitive cTn assays, the 0-hour rule out protocol correctly ruled out 99.6% (95% CI, 98.6%-99.9%), 99.0% (95% CI, 96.9%-99.7%), and 99.1% (95% CI, 97.2%-99.8%) of late presenters; and the 3-hour rule out protocol correctly ruled out 99.4% (95% CI, 98.3%-99.8%), 99.2% (95% CI, 97.3%-99.8%), and 99.0% (95% CI, 97.2%-99.7%) of early presenters. Overall, the 0 h/3 h rule out protocol assigned 40% to 60% of patients to rule out. None of the patients assigned rule out died during 3-months follow-up. CONCLUSIONS: The 0 h/3 h rule out protocol seems to allow the accurate rule out of AMI using both high-sensitivity and sensitive cTn measurements in conjunction with clinical assessment. Additional studies are warranted for external validation.

Cardiac T1 Mapping and Extracellular Volume (ECV) in clinical practice: a comprehensive review.

Cardiovascular Magnetic Resonance is increasingly used to differentiate the aetiology of cardiomyopathies. Late Gadolinium Enhancement (LGE) is the reference standard for non-invasive imaging of myocardial scar and focal fibrosis and is valuable in the differential diagnosis of ischaemic versus non-ischaemic cardiomyopathy. Diffuse fibrosis may go undetected on LGE imaging. Tissue characterisation with parametric mapping methods has the potential to detect and quantify both focal and diffuse alterations in myocardial structure not assessable by LGE. Native and post-contrast T1 mapping in particular has shown promise as a novel biomarker to support diagnostic, therapeutic and prognostic decision making in ischaemic and non-ischaemic cardiomyopathies as well as in patients with acute chest pain syndromes. Furthermore, changes in the myocardium over time may be assessed longitudinally with this non-invasive tissue characterisation method.