Echocardiographic parameters of cardiac structure and function in the diagnosis of acute myocarditis in adult patients: A systematic review and meta-analysis

BACKGROUND

Transthoracic echocardiography (TTE) plays a key role in the initial work-up of myocarditis where the identification of pathologic structural and functional changes may assist in its diagnosis and management. The aim of this systematic review was to appraise the evidence for the utility of echocardiographic parameters of cardiac structure and function in the diagnosis of myocarditis in adult populations.

METHODS

A systematic literature search of medical databases was performed using PRISMA principles to identify all relevant studies assessing TTE parameters in adult patients with myocarditis (1995-2020; English only; PROSPERO registration CRD42021243598). Data for a range of structural and functional TTE parameters were individually extracted and those with low heterogeneity were then meta-analyzed using a random-effects model for effect size, and assessed through standardized mean difference (SMD).

RESULTS

Available data from six studies (with a pooled total of 269 myocarditis patients and 240 controls) revealed that myocarditis can be reliably differentiated from healthy controls using echocardiographic measures of left ventricular (LV) size and systolic function, in particular LV end-diastolic diameter, LV ejection fraction (LVEF) and LV global longitudinal strain (LV-GLS) (p ≤ .01 for all). LV-GLS demonstrated the highest overall effect size, followed by LVEF and LVEDD (SMD: |0.46-1.98|). Two studies also demonstrated that impairment in LV-GLS was associated with adverse cardiovascular outcomes in this population, irrespective of LVEF.

CONCLUSIONS

LV-GLS demonstrated the greatest overall effect size and therefore ability to differentiate myocarditis populations from healthy controls. GLS was also shown to be a predictor of adverse cardiovascular outcomes, in this population.

HIGHTLIGHTS

What is already known on this subject? Myocarditis is a disease process that is often a diagnosis of exclusion, as it frequently mimics other acute cardiac pathologies. Transthoracic echocardiography is traditionally the initial imaging modality used for noninvasive structural assessment in populations with myocarditis. What might this study add? This study demonstrates that left ventricular (LV) global longitudinal strain, LV ejection fraction and LV end-diastolic diameter can differentiate between myocarditis patients and healthy controls. LV-GLS demonstrated the greatest overall effect size when comparing these two populations, in comparison to the other measures. How might this impact on clinical practice? This study demonstrates that assessment of myocardial deformation indices allows for sensitive discrimination between myocarditis patients from healthy controls. Routine assessment of LV-GLS may serve as an important diagnostic tool in the acute care setting.

The impact of empagliflozin and metformin on cardiac parameters in patients with mid-range ejection fraction heart failure without diabetes

Heart failure (HF) remains a significant problem for healthcare systems, requiring the use of intervention and multimodal management strategies. We aimed to assess the short-term effect of empagliflozin (EMPA) and metformin on cardiac function parameters, including ventricular dimension-hypertrophy, septal thickness, ejection fraction (EF), and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in patients with HF and mildly reduced EF. A case-control study included 60 newly diagnosed patients with HF. Patients were divided into two groups: Group E received standard HF treatment (carvedilol, bumetanide, sacubitril-valsartan, spironolactone) plus EMPA 10 mg daily, and Group M received standard HF treatment plus metformin 500 mg daily. After three months of treatment, Group E had a significantly higher EF than Group M compared to initial measurements (a change of 9.2% versus 6.1%, respectively). We found similar results in the left ventricular end-systolic dimension (LVESD), with mean reductions of 0.72 mm for Group E and 0.23 mm for Group M. Regarding cardiac indicators, the level of NT-proBNP was considerably decreased in both groups. However, the reduction was significantly greater in group E than in group M compared to the initial level (mean reduction: 719.9 vs. 973.6, respectively). When combined with quadruple anti-heart failure therapy, metformin enhanced several echocardiographic parameters, showing effects similar to those of EMPA when used in the same treatment regimen. However, the benefits of EMPA were more pronounced, particularly regarding improvements in EF and LVESD.

Prediction of Male Coronary Artery Bypass Grafting Outcomes Using Body Surface Area Weighted Left Ventricular End-diastolic Diameter: Multicenter Retrospective Cohort Study

BACKGROUND

The presence of a high left ventricular end-diastolic diameter (LVEDD) has been linked to a less favorable outcome in patients undergoing coronary artery bypass grafting (CABG) procedures. However, by taking into consideration the reference of left ventricular size and volume measurements relative to the patient's body surface area (BSA), it has been suggested that the accuracy of the predicting outcomes may be improved.

OBJECTIVE

We propose that BSA weighted LVEDD (bLVEDD) is a more accurate predictor of outcomes in patients undergoing CABG compared to simply using LVEDD alone.

METHODS

This study was a comprehensive retrospective cohort study that was conducted across multiple medical centers. The inclusion criteria for this study were patients who were admitted for treatment between October 2016 and May 2021. Only elective surgery patients were included in the study, while those undergoing emergency surgery were not considered. All participants in the study received standard care, and their clinical data were collected through the institutional registry in accordance with the guidelines set forth by the Society of Thoracic Surgeons National Adult Cardiac Database. bLVEDD was defined as LVEDD divided by BSA. The primary outcome was in-hospital all-cause mortality (30 days), and the secondary outcomes were postoperative severe adverse events, including use of extracorporeal membrane oxygenation, multiorgan failure, use of intra-aortic balloon pump, postoperative stroke, and postoperative myocardial infarction.

RESULTS

In total, 9474 patients from 5 centers under the Chinese Cardiac Surgery Registry were eligible for analysis. We found that a high LVEDD was a negative factor for male patients' mortality (odds ratio 1.44, P<.001) and secondary outcomes. For female patients, LVEDD was associated with secondary outcomes but did not reach statistical differences for morality. bLVEDD showed a strong association with postsurgery mortality (odds ratio 2.70, P<.001), and secondary outcomes changed in parallel with bLVEDD in male patients. However, bLVEDD did not reach statistical differences when fitting either mortality or severer outcomes in female patients. In male patients, the categorical bLVEDD showed high power to predict mortality (area under the curve [AUC] 0.71, P<.001) while BSA (AUC 0.62) and LVEDD (AUC 0.64) both contributed to the risk of mortality but were not as significant as bLVEDD (P<.001).

CONCLUSIONS

bLVEDD is an important predictor for male mortality in CABG, removing the bias of BSA and showing a strong capability to accurately predict mortality outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02400125; https://clinicaltrials.gov/ct2/show/NCT02400125.

Baseline QRS duration associates with cardiac recovery in patients with continuous-flow left ventricular assist device implantation

Objective

In chronic heart failure (HF) patients supported with continuous-flow left ventricular assist device (CF-LVAD), we aimed to assess the clinical association of pre-LVAD QRS duration (QRSd) with post-LVAD cardiac recovery, and its correlation with pre- to post-LVAD change in left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD).

Methods

Chronic HF patients (n = 402) undergoing CF-LVAD implantation were prospectively enrolled, at one of the centers comprising the U.T.A.H. (Utah Transplant Affiliated Hospitals) consortium. After excluding patients with acute HF etiologies, hypertrophic or infiltrative cardiomyopathy, and/or inadequate post-LVAD follow up (<3 months), 315 patients were included in the study. Cardiac recovery was defined as LVEF ≥ 40 % and LVEDD < 6 cm within 12 months post-LVAD implantation. Patients fulfilling this condition were termed as responders (R) and results were compared with non-responders (NR).

Results

Thirty-five patients (11 %) achieved 'R' criteria, and exhibited a 15 % shorter QRSd compared to 'NR' (123 ± 37 ms vs 145 ± 36 ms; p < 0.001). A univariate analysis identified association of baseline QRSd with post-LVAD cardiac recovery (OR: 0.986, 95 % CI: 0.976-0.996, p < 0.001). In a multivariate logistic regression model, after adjusting for duration of HF (OR: 0.990, 95 % CI: 0.983-0.997, p = 0.006) and gender (OR: 0.388, 95 % CI: 0.160-0.943, p = 0.037), pre-LVAD QRSd exhibited a significant association with post-LVAD cardiac structural and functional improvement (OR: 0.987, 95 % CI: 0.977-0.998, p = 0.027) and the predictive model showed a c-statistic of 0.73 with p < 0.001. The correlations for baseline QRSd with pre- to post-LVAD change in LVEF and LVEDD were also investigated in 'R' and 'NR' groups.

Conclusion

Chronic advanced HF patients with a shorter baseline QRSd exhibit an increased potential for cardiac recovery after LVAD support.

Leukocytic toll-like receptor 2 knockout protects against diabetes-induced cardiac dysfunction

Diabetic cardiomyopathy is characterized by the deterioration of the myocardial function. Emerging evidences have indicated that leukocytic toll-like receptor 2 (TLR2) played an important role in the development of diabetic cardiomyopathy. Our study aimed to investigate whether TLR2 knockout (KO) exerted a cardioprotective effect in vivo. The establishment of diabetes model was set up in mice via intraperitoneal injection of streptozotocin (STZ). Results demonstrated that blocking of TLR2 significantly suppressed the enhanced left ventricular end-diastolic dimension (LVEDD), left ventricular end systolic diameter (LVESD) and the reduced the heart rate in diabetic cardiomyopathy mice. The decreased resting cell length, PS, TPS and + dL/dt while increased TR90 and - dL/dt caused by diabetic cardiomyopathy were remarkably inhibited by TLR2 KO. Besides that, the alleviated ΔFFI (360/380), decreased SERCA2a and p-NFATc3 expressions, extended Ca²⁺ decay time and elevated Calcineurin A induced by diabetic cardiomyopathy were vastly repressed by TLR2 KO in cardiocytes. Moreover, TLR2 gene silence could ameliorate oxidative stress-induced apoptosis, evidences were the up-regulated superoxide generation and Bax/Bcl-2 expression while restrained GSH/GSSG ratio caused by diabetic cardiomyopathy were tremendously repressed in TLR2 KO mice. Furthermore, blocking of TLR2 remarkably attenuated the augmented fibrosis areas of heart tissues in mice with diabetic cardiomyopathy. The result of the enhanced α-SMA and collagenⅠ caused by diabetic cardiomyopathy were suppressed in heart tissues of TLR2 KO mice further validate it. All in all, our study demonstrated that diabetes-induced cardiac dysfunction could be attenuated by TLR2 KO.

Single-target RNA interference for the blockade of multiple interacting proinflammatory and profibrotic pathways in cardiac fibroblasts. J Mol Cell Cardiol. 2014;66:141-156. [PMID: 24239602 DOI: 10.1016/j.yjmcc.2013.11.004]

Therapeutic targets of broad relevance are likely located in pathogenic pathways common to disorders of various etiologies. Screening for targets of this type revealed CCN genes to be consistently upregulated in multiple cardiomyopathies. We developed RNA interference (RNAi) to silence CCN2 and found this single-target approach to block multiple proinflammatory and profibrotic pathways in activated primary cardiac fibroblasts (PCFBs). The RNAi-strategy was developed in murine PCFBs and then investigated in "individual" human PCFBs grown from human endomyocardial biopsies (EMBs). Screening of short hairpin RNA (shRNA) sequences for high silencing efficacy and specificity yielded RNAi adenovectors silencing CCN2 in murine or human PCFBs, respectively. Comparison of RNAi with CCN2-modulating microRNA (miR) vectors expressing miR-30c or miR-133b showed higher efficacy of RNAi. In murine PCFBs, CCN2 silencing resulted in strongly reduced expression of stretch-induced chemokines (Ccl2, Ccl7, Ccl8), matrix metalloproteinases (MMP2, MMP9), extracellular matrix (Col3a1), and a cell-to-cell contact protein (Cx43), suggesting multiple signal pathways to be linked to CCN2. Immune cell chemotaxis towards CCN2-depleted PCFBs was significantly reduced. We demonstrate here that this RNAi strategy is technically applicable to "individual" human PCFBs, too, but that these display individually strikingly different responses to CCN2 depletion. Either genomically encoded factors or stable epigenetic modification may explain different responses between individual PCFBs. The new RNAi approach addresses a key regulator protein induced in cardiomyopathies. Investigation of this and other molecular therapies in individual human PCBFs may help to dissect differential pathogenic processes between otherwise similar disease entities and individuals.

Ventricular premature depolarization QRS duration as a new marker of risk for the development of ventricular premature depolarization-induced cardiomyopathy

BACKGROUND

Frequent ventricular premature depolarizations (VPDs) can cause cardiomyopathy (CMP). The mechanisms underlying its development remain unclear, with VPD burden being only a weak predictor of risk.

OBJECTIVE

To determine whether VPD QRS duration at the time of initial presentation could predict risk for the subsequent development of CMP in patients with normal left ventricular ejection fraction (LVEF).

METHODS

From consecutive patients referred for ablation between January 1, 2006, and April 2, 2013, with ≥10% VPDs on 24-hour Holter monitoring, we identified 45 patients with normal LVEF and an electrocardiogram of the targeted VPD, who were then followed for at least 6 months (median 14 months; interquartile range [IQR] 8-32 months) before intervention. We excluded patients with structural or genetic heart disease.

RESULTS

Of the 45 patients, 28 (62%) maintained normal LVEF and 17(38%) developed VPD-induced CMP. VPD burden was similar (26.5% [IQR 19.3%-39.5%] vs 26.0% [IQR 16.4%-41.0%]; P = 0.4) between the 2 groups. Patients who developed VPD-induced CMP had significantly longer VPD QRS duration (159 ms vs 142 ms; P < .001) and a longer sinus QRS duration (97 ms vs 89 ms; P = .04). A VPD QRS duration of ≥153 ms best predicted development of VPD CMP (82% sensitivity and 75% specificity). Longer VPD QRS duration and a non-outflow tract site of VPD origin were independent risk factors for left ventricular dysfunction after multivariate analysis.

CONCLUSION

VPD QRS duration longer than 153 ms and a non-outflow tract site of origin might be useful predictors of the subsequent development of VPD-induced CMP.

Relation between genotype and left-ventricular dilatation in patients with Marfan syndrome

Cardiovascular manifestations in patients with Marfan syndrome (MFS) are related to aortic and valvular abnormalities. However, dilatation of the left ventricle (LV) can occur, even in the absence of aortic surgery or valvular abnormalities. We evaluated genetic characteristics of patients with MFS with LV dilatation. One hundred eighty-two patients fulfilling the MFS criteria, without valvular abnormalities or previous aortic surgery, with a complete FBN1 analysis, were studied. FBN1 mutations were identified in over 81% of patients. Twenty-nine patients (16%) demonstrated LV dilatation (LV end diastolic diameter corrected for age and body surface area >112%). FBN1-positive patients carrying a non-missense mutation more often had LV dilatation than missense mutation carriers (14/74 versus 5/75; p<0.05). Finally, FBN1-negative MFS patients significantly more often demonstrated LV dilatation than FBN1-positive patients (10/33 versus 19/149; p<0.05). It is concluded that LV dilatation in MFS patients is more often seen in patients with a non-missense mutation and in those patients without an FBN1 mutation. Therefore physicians should be aware of the possibility of LV dilatation in these patients even in the absence of valvular pathology.

Relative efficacy of catheter ablation vs antiarrhythmic drugs in treating premature ventricular contractions: a single-center retrospective study

BACKGROUND

It is unknown whether radiofrequency ablation (RFA) or antiarrhythmic therapy is superior when treating patients with symptomatic premature ventricular contractions (PVCs).

OBJECTIVE

To determine the relative efficacy of RFA and antiarrhythmic drugs (AADs) on PVC burden reduction and increasing left ventricular systolic function.

METHODS

Patients with frequent PVCs (>1000/24 h) were treated either by RFA or with AADs from January 2005 through December 2010. Data from 24-hour Holter monitoring and echocardiography before and 6-12 months after treatment were compared between the 2 groups.

RESULTS

Of 510 patients identified, 215 (40%) underwent RFA and 295 (60%) received AADs. The reduction in PVC frequency was greater by RFA than with AADs (-21,799/24 h vs -8,376/24 h; P < .001). The left ventricular ejection fraction (LVEF) was increased significantly after RFA (53%-56%; P < .001) but not after AAD (52%- 52%; P = .6) therapy. Of 121 (24%) patients with reduced LVEF, 39 (32%) had LVEF normalization to 50% or greater. LVEF was restored in 25 of 53 (47%) patients in the RFA group compared with 14 of 68 (21%) patients in the AAD group (P = .003). PVC coupling interval less than 450 ms, less impaired left ventricular function, and RFA were independent predictors of LVEF normalization performed by using multivariate analysis.

CONCLUSION

RFA appears to be more effective than AADs in PVC reduction and LVEF normalization.

Candidate gene approach to identifying rare genetic variants associated with lone atrial fibrillation

BACKGROUND

Rare variants in candidate atrial fibrillation (AF) genes have been associated with AF in small kindreds. The extent to which such polymorphisms contribute to AF is unknown.

OBJECTIVE

The purpose of this study was to determine the spectrum and prevalence of rare amino acid coding (AAC) variants in candidate AF genes in a large cohort of unrelated lone AF probands.

METHODS

We resequenced 45 candidate genes in 303 European American (EA) lone AF probands (186 lone AF probands screened for each gene on average [range 89-303], 63 screened for all) identified in the Vanderbilt AF Registry (2002-2012). Variants detected were screened against 4300 EAs from the Exome Sequencing Project (ESP) to identify very rare (minor allele frequency ≤0.04%) AAC variants and these were tested for AF co-segregation in affected family members where possible.

RESULTS

Median age at AF onset was 46.0 years [interquartile range 33.0-54.0], and 35.6% had a family history of AF. Overall, 63 very rare AAC variants were identified in 60 of 303 lone AF probands, and 10 of 19 (52.6%) had evidence of co-segregation with AF. Among the 63 lone AF probands who had 45 genes screened, the very rare variant burden was 22%. Compared with the 4300 EA ESP, the proportion of lone AF probands with a very rare AAC variant in CASQ2 and NKX2-5 was increased 3-5-fold (P <.05).

CONCLUSION

No very rare AAC variants were identified in ~80% of lone AF probands. Potential reasons for the lack of very rare AAC variants include a complex pattern of inheritance, variants in as yet unidentified AF genes or in noncoding regions, and environmental factors.

Surgical technique influences HeartMate II left ventricular assist device thrombosis

BACKGROUND

Thrombosis of the HeartMate II (HM2 [Thoratec Corporation, Pleasanton, CA]) is a potentially devastating complication. While attention has been focused on anticoagulation strategies to prevent this complication, the impact of surgical technique has not been assessed.

METHODS

Patients undergoing HM2 implantation at two institutions were reviewed. Pump thrombosis (PT) was defined as a clinical syndrome that included more than 30% elevation in pump power, more than 30% elevation in lactate dehydrogenase, and greater than 20% decrease in hemoglobin with the presence of thrombus in the HM2 stator or rotor, or both, at explant or autopsy. A blinded clinician reviewed dimensions and angles of the HM2 obtained from chest x-ray films. Patients demonstrating PT were compared with patients having normal function.

RESULTS

Of the 49 patients reviewed, 11 (22.4%) displayed evidence of PT at a median of 42 days after HM2 implantation. Patient with PT had greater acute angulation of the HM2 inflow cannula immediately postoperatively (48.2 ± 6.8 versus 65.4 ± 9.2 degrees, p < 0.001) and after 30 days (50.1 ± 8.0 versus 65.1 ± 9.9 degrees, p < 0.001). Pump pocket depth was lower in the PT group immediately after HM2 implantation (107.0 ± 41.9 versus 144.3 ± 20.3 cm, p < 0.001) and after 30 days (86.0 ± 39.1 versus 113.1 ± 25.4 cm, p = 0.02). Patients with evidence of PT did not have a decrease in end-diastolic diameter (76 ± 9 versus 70 ± 15 mm, p = 0.24) whereas patients in the normal function group had effective remodeling of the left ventricle (70 ± 10 versus 56 ± 12 mm, p = 0.01).

CONCLUSIONS

Meticulous surgical technique, which necessitates creating an adequately sized pump pocket and appropriately directing the inflow cannula at the time of operation, may reduce the risk of PT.

Senescence marker protein 30 inhibits angiotensin II-induced cardiac hypertrophy and diastolic dysfunction

BACKGROUND AND OBJECTIVE

Senescence marker protein 30 (SMP30) is assumed to behave as an anti-aging factor. Recently, we have demonstrated that deficiency of SMP30 exacerbates angiotensin II-induced cardiac hypertrophy, dysfunction and remodeling, suggesting that SMP30 may have a protective role in the heart. Thus, this study aimed to test the hypothesis that up-regulation of SMP30 inhibits cardiac adverse remodeling in response to angiotensin II.

METHODS

We generated transgenic mice with cardiac-specific overexpression of SMP30 gene using α-myosin heavy chain promoter. Transgenic mice and wild-type littermate mice were subjected to continuous angiotensin II infusion (800 ng/kg/min).

RESULTS

After 14 days, heart weight and left ventricular weight were lower in transgenic mice than in wild-type mice, although blood pressure was similarly elevated during angiotensin II infusion. Cardiac hypertrophy and diastolic dysfunction in response to angiotensin II were prevented in transgenic mice compared with wild-type mice. The degree of cardiac fibrosis by angiotensin II was lower in transgenic mice than in wild-type mice. Angiotensin II-induced generation of superoxide and subsequent cellular senescence were attenuated in transgenic mouse hearts compared with wild-type mice.

CONCLUSIONS

Cardiac-specific overexpression of SMP30 inhibited angiotensin II-induced cardiac adverse remodeling. SMP30 has a cardio-protective role with anti-oxidative and anti-aging effects and could be a novel therapeutic target to prevent cardiac hypertrophy and remodeling due to hypertension.

Detection of a large duplication mutation in the myosin-binding protein C3 gene in a case of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a cardiovascular disease with autosomal dominant inheritance caused by mutations in genes coding for sarcomeric and/or regulatory proteins expressed in cardiomyocytes. In a small cohort of HCM patients (n=8), we searched for mutations in the two most common genes responsible for HCM and found four missense mutations in the MYH7 gene encoding cardiac β-myosin heavy chain (R204H, M493V, R719W, and R870H) and three mutations in the myosin-binding protein C3 gene (MYBPC3) including one missense (A848V) and two frameshift mutations (c.3713delTG and c.702ins26bp). The c.702ins26bp insertion resulted from the duplication of a 26-bp fragment in a 54-year-old female HCM patient presenting with clinical signs of heart failure due to diastolic dysfunction. Although such large duplications (>10 bp) in the MYBPC3 gene are very rare and have been identified only in 4 families reported so far, the identical duplication mutation was found earlier in a Dutch patient, demonstrating that it may constitute a hitherto unknown founder mutation in central European populations. This observation underscores the significance of insertions into the coding sequence of the MYBPC3 gene for the development and pathogenesis of HCM.

Dose-dependent diastolic dysfunction and early death in a mouse model with cardiac troponin mutations

Our aim was to explore the dose-dependent diastolic dysfunction and the mechanisms of heart failure and early death in transgenic (TG) mice modeling human restrictive cardiomyopathy (RCM). The first RCM mouse model (cTnI(193His) mice) carrying cardiac troponin I (cTnI) R193H mutation (mouse cTnI R193H equals to human cTnI R192H) was generated several years ago in our laboratory. The RCM mice manifested a phenotype similar to that observed in RCM patients carrying the same cTnI mutation, i.e. enlarged atria and restricted ventricles. However, the causes of heart failure and early death observed in RCM mice remain unclear. In this study, we have produced RCM TG mice (cTnI(193His)-L, cTnI(193His)-M and cTnI(193His)-H) that express various levels of mutant cTnI in the heart. Histological examination and echocardiography were performed on these mice to monitor the time course of the disease development and heart failure. Our data demonstrate that cTnI mutation-caused diastolic dysfunction is dose-dependent. The key mechanism is myofibril hypersensitivity to Ca(2+) resulting in an impaired relaxation in the mutant cardiac myocytes. Prolonged relaxation time and delay of Ca(2+) decay observed in the mutant cardiac myocytes are correlated with the level of the mutant protein in the heart. Markedly enlarged atria due to the elevated end-diastolic pressure and myocardial ischemia are observed in the heart of the transgenic mice. In the mice with the highest level of the mutant protein, restricted ventricles and systolic dysfunction occur followed immediately by heart failure and early death. Diastolic dysfunction caused by R193H troponin I mutation is specific, showing a dose-dependent pattern. These mouse models are useful tools for the study of diastolic dysfunction. Impaired diastole can cause myocardial ischemia and fibrosis formation, resulting in the development of systolic dysfunction and heart failure with early death in the RCM mice with a high level of the mutant protein in the heart.

Echo-Doppler assessment of arterial stiffness in pediatric patients with Kawasaki disease

BACKGROUND

There is growing evidence to suggest increased arterial stiffness in patients with a history of Kawasaki disease (KD). Pulse-wave velocity (PWV) is the most validated measure of arterial stiffness. The aim of this study was to determine if aortic PWV is increased in children with KD.

METHODS

This was a retrospective cohort study. The study cohort was composed of 42 patients with KD (mean age, 9.7 ± 2.0 years) and 44 age-matched control subjects. The primary measure was aortic PWV. Secondary measures included characteristic impedance (Zc), input impedance (Zi), elastic pressure-strain modulus (Ep), and β stiffness index and the following measures of left ventricular size and function: end-diastolic and end-systolic dimensions, wall thickness in diastole and systole, mass, shortening and ejection fractions, mean velocity of circumferential fiber shortening, and stress at peak systole. The appropriate measures were indexed to body surface area. The aortic stiffness and impedance indexes were derived using an echocardiography-Doppler method.

RESULTS

Height, weight, body mass index, and body surface area were similar between the groups. PWV was higher in patients with KD compared with controls (495 vs 370 cm/sec, P = .0008). Zc, Ep, and β stiffness index were higher in patients with KD, but the difference was not statistically significant. Left ventricular dimensions were all within normal limits, with no differences between the groups. Patients with KD had lower stress at peak systole compared with controls (55 vs 64 g/cm(2), P = .01). There was a significant association between the length of time between the initial diagnosis and testing with PWV (r = 0.32, P = .04) and Zi (r = -0.38, P = .01) in patients with KD. There was no significant association between the arterial stiffness indexes (PWV, Zi, Zc, Ep, and β stiffness index) and length of fever, age at KD diagnosis, or heart rate. Logistic regression analysis revealed no association between coronary artery lesion classification and length of fever, day of illness at first treatment, age at KD diagnosis, or any of the arterial stiffness indexes. In the control group, there were significant associations between age and heart rate (r = -0.48, P = .001), Zi (r = -0.55, P < .0001), Zc (r = -0.66, P < .0001), and β stiffness index (r = -0.31, P = .04). There was an association between heart rate and Zc (r = 0.44, P = .003) but no association between heart rate and PWV, Zi, Ep, or β stiffness index.

CONCLUSIONS

Arterial stiffness was increased in children with KD. There was no association between acute-phase KD coronary involvement and PWV. This implies that patients with KD may be at increased cardiovascular risk in the future.

Significance of high-sensitivity cardiac troponin T in hypertrophic cardiomyopathy

OBJECTIVES

This study investigated the significance of the serum high-sensitivity cardiac troponin T (hs-cTnT) marker for prediction of adverse events in hypertrophic cardiomyopathy (HCM).

BACKGROUND

Although serum cardiac troponins as sensitive and specific markers of myocardial injury have become well-established diagnostic and prognostic markers in acute coronary syndrome, the usefulness of hs-cTnT for prediction of cardiovascular events in patients with HCM is unclear.

METHODS

We performed clinical evaluation, including measurements of hs-cTnT in 183 consecutive patients with HCM.

RESULTS

Of 183 HCM patients, 99 (54%) showed abnormal hs-cTnT values (>0.014 ng/ml). During a mean follow-up of 4.1 ± 2.0 years, 32 (32%) of the 99 patients in the abnormal hs-cTnT group, but only 6 (7%) of 84 patients with normal hs-cTnT values, experienced cardiovascular events: cardiovascular deaths, unplanned heart failure admissions, sustained ventricular tachycardia, embolic events, and progression to New York Heart Association functional class III or IV status (hazard ratio [HR]: 5.05, p < 0.001). Abnormal hs-cTnT value remained an independent predictor of these cardiovascular events after multivariate analysis (HR: 3.23, p = 0.012). Furthermore, in the abnormal hs-cTnT group, overall risk increased with an increase in hs-cTnT value (HR: 1.89/hs-cTnT 1 SD increase in the logarithmic scale, 95% confidence interval: 1.13 to 3.15; p = 0.015 [SD: 0.59]).

CONCLUSIONS

In patients with HCM, an abnormal serum concentration of hs-cTnT is an independent predictor of adverse outcome, and a higher degree of abnormality in hs-cTnT value is associated with a greater risk of cardiovascular events.

Association of body surface area and body composition with heart structural characteristics of female swimmers

In healthy nonathletic populations, some left ventricle (LV) parameters such as LV mass (LVM) and LV end diastolic dimension (LVEDD) can be predicted by some of body size parameters such as body surface area (BSA), fat-free mass (FFM), and height (H). These body size parameters use to remove covariate influence of body size from cardiac dimension variables and allow comparisons to be made between individuals and groups of different body size. Endurance exercise has been associated with changes in LV size and body composition of athletes. The aim of this study was to evaluate in 30 trained female swimmers (12-17 y) possible correlations between BSA, FFM, fat mass (FM) determined by bioelectrical impedance analyzer(BIA); and a range of cardiac dimensions derived by echocardiography. Univariate correlations were studied between left ventricular and body size variables. Stepwise multiple linear regression was performed to determine the best determinants of LV variables. LVM and LVEDD had a significant relation with FFM (P<0.001) and BSA (p<0.05). Left ventricle posterior wall thickness (PWT) had a significant relation with BSA (p<0.001) and FFM (p<0.005). No relation was found between heart's structural variable (LVM, LVEDD, LVESD and PWT) and FM. Using a multivariate regression analysis, FFM was the only independent predictor of both LVM (R2=0.541, P<0.001) and LVEDD (R2=0.189, P<0.05). These results suggest that Correction of LVM and LVEDD by FFM in athletes may be more appropriate than other measures of body size for indexing absolute amounts of LV dimension. Yet further researches in other athletes are required to confirm these findings.