Prognostic value of left ventricular hypertrophy and geometry in patients with a first, uncomplicated myocardial infarction

Short-Term Blockade of Pro-Inflammatory Alarmin S100A9 Favorably Modulates Left Ventricle Proteome and Related Signaling Pathways Involved in Post-Myocardial Infarction Recovery

Prognosis after myocardial infarction (MI) varies greatly depending on the extent of damaged area and the management of biological processes during recovery. Reportedly, the inhibition of the pro-inflammatory S100A9 reduces myocardial damage after MI. We hypothesize that a S100A9 blockade induces changes of major signaling pathways implicated in post-MI healing. Mass spectrometry-based proteomics and gene analyses of infarcted mice left ventricle were performed. The S100A9 blocker (ABR-23890) was given for 3 days after coronary ligation. At 3 and 7 days post-MI, ventricle samples were analyzed versus control and Sham-operated mice. Blockade of S100A9 modulated the expressed proteins involved in five biological processes: leukocyte cell–cell adhesion, regulation of the muscle cell apoptotic process, regulation of the intrinsic apoptotic signaling pathway, sarcomere organization and cardiac muscle hypertrophy. The blocker induced regulation of 36 proteins interacting with or targeted by the cellular tumor antigen p53, prevented myocardial compensatory hypertrophy, and reduced cardiac markers of post-ischemic stress. The blockade effect was prominent at day 7 post-MI when the quantitative features of the ventricle proteome were closer to controls. Blockade of S100A9 restores key biological processes altered post-MI. These processes could be valuable new pharmacological targets for the treatment of ischemic heart. Mass spectrometry data are available via ProteomeXchange with identifier PXD033683.

Predicting peri-operative troponin elevation by advanced electrocardiography

BACKGROUND

Peri-operative mortality remains a global problem and an improved pre-operative risk assessment identifying those at highest risk for peri-operative myocardial injury might improve postsurgical outcomes.

AIMS

To determine whether pre-operative measures of advanced electrocardiography (A-ECG) could predict elevated serum troponin T (TnT) in patients undergoing elective, major non-cardiac surgery.

MATERIAL AND METHODS

This observational cohort study included 257 surgical patients who underwent elective major non-cardiac surgery between the years 2012-2013 and 2015-2016 at Karolinska University Hospital. All selected patients were ≥ 18 years of age [median age 70 (63-75) years], had a pre-operative digital 12‑lead ECG < 6 months prior to the procedure and a postoperative high-sensitivity cardiac TnT (hs-cTnT) sample. A-ECG confounders including atrial fibrillation or flutter, abundant premature atrial or ventricular contractions, bundle branch blocks, QRS duration >110 ms, heart rate > 100 beats/min and paced rhythms were excluded. Previously validated A-ECG diagnostic scores that detect cardiovascular pathologies were calculated and compared in patients with and without peri-operative myocardial injury, defined as hs-cTnT >14 ng l^-1.

RESULTS

Pre-operative left ventricular systolic dysfunction by A-ECG was more probable in patients with than without peri-operative myocardial injury (p = 0.03).

CONCLUSIONS

While a pre-operative A-ECG score for LVSD was able to differentiate between patients with versus without elevated peri-operative TnT levels, it did not add any further utility to standard clinical parameters for predicting troponin-related events in the studied population.

Pretransplant left ventricular hypertrophy in association with postoperative myocardial injury in liver transplantation

Pretransplant left ventricular hypertrophy (LVH) is a common finding during preoperative cardiac evaluation. We hypothesized that patients with pretransplant LVH were associated with a higher risk of postoperative myocardial injury (PMI) in adult patients undergoing liver transplantation (LT). A retrospective cohort analysis was performed by reviewing the medical records of adult patients who underwent LT between January 2006 and October 2013. Of 893 patients, the incidences of mild, moderate, and severe LVH were 7.8%, 5.6%, and 2.5%, respectively. Propensity match was used to eliminate the pretransplant imbalance between the LVH and non-LVH groups. In after-match patients, 23.5% of LVH patients developed PMI compared to 11.8% in the control group (P = .011). The incidence of PMI in patients with moderate-severe degrees of LVH was significantly higher compared with that in patients with mild LVH (27.9% vs 19.1%, P = .016). When controlling intraoperative variables, patients with LVH had 4.5 higher odds of developing PMI (95% CI1.18-17.19, P = .028). Patients experiencing PMI had significantly higher 1-year mortality (37.5% vs 15.7%, log-rank test P < .001). Our results suggest that patients with pretransplant LVH were at a high risk of developing PMI and should be monitored closely in the perioperative period. More studies are warranted.

Ultrasound and Microbubble-targeted Delivery of a microRNA Inhibitor to the Heart Suppresses Cardiac Hypertrophy and Preserves Cardiac Function

MicroRNAs (miRs) are dysregulated in pathological left ventricular hypertrophy. AntimiR inhibition of miR-23a suppressed hypertension-induced cardiac hypertrophy in preclinical models, but clinical translation is limited by a lack of cardiac-targeted delivery systems. Ultrasound-targeted microbubble cavitation (UTMC) utilizes microbubbles as nucleic acid carriers to target delivery of molecular therapeutics to the heart. The objective of this study was to evaluate the efficacy of UTMC targeted delivery of antimiR-23a to the hearts of mice for suppression of hypertension-induced cardiac hypertrophy.

Methods: Cationic lipid microbubbles were loaded with 300 pmol negative control antimiR (NC) or antimiR-23a. Mice received continuous phenylephrine infusion via implanted osmotic minipumps, then UTMC treatments with intravenously injected antimiR-loaded microbubbles 0, 3, and 7 days later. At 2 weeks, hearts were harvested and miR-23a levels were measured. Left ventricular (LV) mass and function were assessed with echocardiography.

Results: UTMC treatment with antimiR-23a decreased cardiac miR-23a levels by 41 ± 8% compared to UTMC + antimiR-NC controls (p < 0.01). Furthermore, LV mass after 1 week of phenylephrine treatment was 17 ± 10% lower following UTMC + antimiR-23a treatment compared to UTMC + antimiR-NC controls (p = 0.02). At 2 weeks, fractional shortening was 23% higher in the UTMC + antimiR-23a mice compared to UTMC + antimiR-NC controls (p < 0.01).

Conclusions: UTMC is an effective technique for targeted functional delivery of antimiRs to the heart causing suppression of cardiac hypertrophy and preservation of systolic function. This approach could represent a revolutionary therapy for patients suffering from pathological cardiac hypertrophy and other cardiovascular conditions.

Hypertrophied myocardium is vulnerable to ischemia/reperfusion injury and refractory to rapamycin-induced protection due to increased oxidative/nitrative stress

Left ventricular hypertrophy (LVH) is causally related to increased morbidity and mortality following acute myocardial infarction (AMI) via still unknown mechanisms. Although rapamycin exerts cardioprotective effects against myocardial ischemia/reperfusion (MI/R) injury in normal animals, whether rapamycin-elicited cardioprotection is altered in the presence of LVH has yet to be determined. Pressure overload induced cardiac hypertrophied mice and sham-operated controls were exposed to AMI by coronary artery ligation, and treated with vehicle or rapamycin 10 min before reperfusion. Rapamycin produced marked cardioprotection in normal control mice, whereas pressure overload induced cardiac hypertrophied mice manifested enhanced myocardial injury, and was refractory to rapamycin-elicited cardioprotection evidenced by augmented infarct size, aggravated cardiomyocyte apoptosis, and worsening cardiac function. Rapamycin alleviated MI/R injury via ERK-dependent antioxidative pathways in normal mice, whereas cardiac hypertrophied mice manifested markedly exacerbated oxidative/nitrative stress after MI/R evidenced by the increased iNOS/gp91^phox expression, superoxide production, total NO metabolites, and nitrotyrosine content. Moreover, scavenging superoxide or peroxynitrite by selective gp91^phox assembly inhibitor gp91ds-tat or ONOO^- scavenger EUK134 markedly ameliorated MI/R injury, as shown by reduced myocardial oxidative/nitrative stress, alleviated myocardial infarction, hindered cardiomyocyte apoptosis, and improved cardiac function in aortic-banded mice. However, no additional cardioprotective effects were achieved when we combined rapamycin and gp91ds-tat or EUK134 in ischemic/reperfused hearts with or without LVH. These results suggest that cardiac hypertrophy attenuated rapamycin-induced cardioprotection by increasing oxidative/nitrative stress and scavenging superoxide/peroxynitrite protects the hypertrophied heart from MI/R.

Current Perspectives on Systemic Hypertension in Heart Failure with Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is a prevalent but incompletely understood syndrome. Traditional models of HFpEF pathophysiology revolve around systemic HTN and other causes of increased left ventricular afterload leading to left ventricular hypertrophy (LVH) and diastolic dysfunction. However, emerging models attribute the development of HFpEF to systemic proinflammatory changes secondary to common comorbidities which include HTN. Alterations in passive ventricular stiffness, ventricular-arterial coupling, peripheral microvascular function, systolic reserve, and chronotropic response occur. As a result, HFpEF is heterogeneous in nature, making it difficult to prescribe uniform therapies to all patients. Nonetheless, treating systemic HTN remains a cornerstone of HFpEF management. Antihypertensive therapies have been linked to LVH regression and improvement in diastolic dysfunction. However, to date, no therapies have definitive mortality benefit in HFpEF. Non-pharmacologic management for HTN, including dietary modification, exercise, and treating sleep disordered breathing, may provide some morbidity benefit in the HFpEF population. Future research is need to identify effective treatments, perhaps in more specific subgroups, and focus may need to shift from reducing mortality to improving exercise capacity and symptoms. Tailoring antihypertensive therapies to specific phenotypes of HFpEF may be an important component of this strategy.

Predictors of left ventricular remodeling after ST-elevation myocardial infarction

Adverse left ventricular (LV) remodeling after acute ST-elevation myocardial infarction (STEMI) is associated with morbidity and mortality. We studied clinical, biochemical and angiographic determinants of LV end diastolic volume index (LVEDVi), end systolic volume index (LVESVi) and mass index (LVMi) as global LV remodeling parameters 4 months after STEMI, as well as end diastolic wall thickness (EDWT) and end systolic wall thickness (ESWT) of the non-infarcted myocardium, as compensatory remote LV remodeling parameters. Data was collected in 271 patients participating in the GIPS-III trial, presenting with a first STEMI. Laboratory measures were collected at baseline, 2 weeks, and 6–8 weeks. Cardiovascular magnetic resonance imaging (CMR) was performed 4 months after STEMI. Linear regression analyses were performed to determine predictors. At baseline, patients were 21% female, median age was 58 years. At 4 months, mean LV ejection fraction (LVEF) was 54 ± 9%, mean infarct size was 9.0 ± 7.9% of LVM. Strongest univariate predictors (all p < 0.001) were peak Troponin T for LVEDVi (R² = 0.26), peak CK-MB for LVESVi (R² = 0.41), NT-proBNP at 2 weeks for LVMi (R² = 0.24), body surface area for EDWT (R² = 0.32), and weight for ESWT (R² = 0.29). After multivariable analysis, cardiac biomarkers remained the strongest predictors of LVMi, LVEDVi and LVESVi. NT-proBNP but none of the acute cardiac injury biomarkers were associated with remote LV wall thickness. Our analyses illustrate the value of cardiac specific biochemical biomarkers in predicting global LV remodeling after STEMI. We found no evidence for a hypertrophic response of the non-infarcted myocardium.

Response of the human myocardium to ischemic injury and preconditioning: The role of cardiac and comorbid conditions, medical treatment, and basal redox status

BACKGROUND

The diseased human myocardium is highly susceptible to ischemia/reoxygenation (I/R)-induced injury but its response to protective interventions such as ischemic preconditioning (IPreC) is unclear. Cardiac and other pre-existing clinical conditions as well as previous or ongoing medical treatment may influence the myocardial response to I/R injury and protection. This study investigated the effect of both on myocardial susceptibility to I/R-induced injury and the protective effects of IPreC.

METHODS AND RESULTS

Atrial myocardium from cardiac surgery patients (n = 300) was assigned to one of three groups: aerobic control, I/R alone, and IPreC. Lactate dehydrogenase leakage, as a marker of cell injury, and cell viability were measured. The basal redox status was determined in samples from 90 patients. The response to I/R varied widely. Myocardium from patients with aortic valve disease was the most susceptible to injury whereas myocardium from dyslipidemia patients was the least susceptible. Tissue from females was better protected than tissue from males. Myocardium from patients with mitral valve disease was the least responsive to IPreC. The basal redox status was altered in the myocardium from patients with mitral and aortic valve disease.

CONCLUSIONS

The response of the myocardium to I/R and IPreC is highly variable and influenced by the underlying cardiac pathology, dyslipidemia, sex, and the basal redox status. These results should be taken into account in the design of future clinical studies on the prevention of I/R injury and protection.

Wave intensity analysis and its application to the coronary circulation

Wave intensity analysis (WIA) is a technique developed from the field of gas dynamics that is now being applied to assess cardiovascular physiology. It allows quantification of the forces acting to alter flow and pressure within a fluid system, and as such it is highly insightful in ascribing cause to dynamic blood pressure or velocity changes. When co-incident waves arrive at the same spatial location they exert either counteracting or summative effects on flow and pressure. WIA however allows waves of different origins to be measured uninfluenced by other simultaneously arriving waves. It therefore has found particular applicability within the coronary circulation where both proximal (aortic) and distal (myocardial) ends of the coronary artery can markedly influence blood flow. Using these concepts, a repeating pattern of 6 waves has been consistently identified within the coronary arteries, 3 originating proximally and 3 distally. Each has been associated with a particular part of the cardiac cycle. The most clinically relevant wave to date is the backward decompression wave, which causes the marked increase in coronary flow velocity observed at the start of the diastole. It has been proposed that this wave is generated by the elastic re-expansion of the intra-myocardial blood vessels that are compressed during systolic contraction. Particularly by quantifying this wave, WIA has been used to provide mechanistic and prognostic insight into a number of conditions including aortic stenosis, left ventricular hypertrophy, coronary artery disease and heart failure. It has proven itself to be highly sensitive and as such a number of novel research directions are encouraged where further insights would be beneficial.

Left Ventricular Hypertrophy Is Associated With Increased Infarct Size and Decreased Myocardial Salvage in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Approximately one third of patients with ST-segment elevation myocardial infarction (STEMI) have left ventricular hypertrophy (LVH), which is associated with impaired outcome. However, the causal association between LVH and outcome in STEMI is unknown. We evaluated the association between LVH and: myocardial infarct size, area at risk, myocardial salvage, microvascular obstruction, left ventricular (LV) function (all determined by cardiac magnetic resonance [CMR]), and all-cause mortality and readmission for heart failure in STEMI patients treated with primary percutaneous coronary intervention.

METHODS AND RESULTS

In this substudy of the DANAMI-3 trial, 764 patients underwent CMR. LVH was defined by CMR and considered present if LV mass exceeded 77 (men) and 67 g/m2 (women). One hundred seventy-eight patients (24%) had LVH. LVH was associated with a larger final infarct size (15% [interquartile range {IQR}, 10-21] vs 9% [IQR, 3-17]; P<0.001) and smaller final myocardial salvage index (0.6 [IQR, 0.5-0.7] vs 0.7 [IQR, 0.5-0.9]; P<0.001). The LVH group had a higher incidence of microvascular obstruction (66% vs 45%; P<0.001) and lower final LV ejection fraction (LVEF; 53% [IQR, 47-60] vs 61% [IQR, 55-65]; P<0.001). In a Cox regression analysis, LVH was associated with a higher risk of all-cause mortality and readmission for heart failure (hazard ratio 2.59 [95% CI, 1.38-4.90], P=0.003). The results remained statistically significant in multivariable models.

CONCLUSIONS

LVH is independently associated with larger infarct size, less myocardial salvage, higher incidence of microvascular obstruction, lower LVEF, and a higher risk of all-cause mortality and incidence of heart failure in STEMI patients treated with primary percutaneous coronary intervention.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01435408.

Impact of left ventricular hypertrophy on troponin release during acute myocardial infarction: new insights from a comprehensive translational study

BACKGROUND

Biomarkers are frequently used to estimate infarct size (IS) as an endpoint in experimental and clinical studies. Here, we prospectively studied the impact of left ventricular (LV) hypertrophy (LVH) on biomarker release in clinical and experimental myocardial infarction (MI).

METHODS AND RESULTS

ST-segment elevation myocardial infarction (STEMI) patients (n=140) were monitored for total creatine kinase (CK) and cardiac troponin I (cTnI) over 72 hours postinfarction and were examined by cardiac magnetic resonance (CMR) at 1 week and 6 months postinfarction. MI was generated in pigs with induced LVH (n=10) and in sham-operated pigs (n=8), and serial total CK and cTnI measurements were performed and CMR scans conducted at 7 days postinfarction. Regression analysis was used to study the influence of LVH on total CK and cTnI release and IS estimated by CMR (gold standard). Receiver operating characteristic (ROC) curve analysis was performed to study the discriminatory capacity of the area under the curve (AUC) of cTnI and total CK in predicting LV dysfunction. Cardiomyocyte cTnI expression was quantified in myocardial sections from LVH and sham-operated pigs. In both the clinical and experimental studies, LVH was associated with significantly higher peak and AUC of cTnI, but not with differences in total CK. ROC curves showed that the discriminatory capacity of AUC of cTnI to predict LV dysfunction was significantly worse for patients with LVH. LVH did not affect the capacity of total CK to estimate IS or LV dysfunction. Immunofluorescence analysis revealed significantly higher cTnI content in hypertrophic cardiomyocytes.

CONCLUSIONS

Peak and AUC of cTnI both significantly overestimate IS in the presence of LVH, owing to the higher troponin content per cardiomyocyte. In the setting of LVH, cTnI release during STEMI poorly predicts postinfarction LV dysfunction. LV mass should be taken into consideration when IS or LV function are estimated by troponin release.

Subclassification of left ventricular hypertrophy based on dilation stratifies coronary artery disease patients with distinct risk

BACKGROUND

A new 4-tired classification of left ventricular hypertrophy (LVH) based on LV concentricity and dilation has been proposed; however, the association between the new categorization of LV geometry and outcomes in patients with coronary artery disease (CAD) is still unknown.

METHODS

All the 2297 patients with CAD included underwent echocardiographic examination prior to discharge. Left ventricular mass (LVM) was calculated, and left ventricular end-diastolic volume (EDV) was indexed by body surface area (BSA). Study cohort was divided into five groups according to LV geometry: (i) eccentric nondilated LVH (normal LVM/EDV((2/3)) and EDV/BSA) (n = 129); (ii) eccentric dilated LVH (normal LVM/EDV((2/3)) with increased EDV/BSA) (n = 222); (iii) concentric nondilated LVH (increased LVM/EDV((2/3)) with normal EDV/BSA) (n = 441); (iv) concentric dilated LVH (increased LVM/EDV((2/3)) and EDV/BSA) (n = 118); and (v) normal LV mass (n = 1387).

RESULTS

Dilated LVH was associated with a higher event rates of all-cause death (eccentric 13·1% vs. 3·1%; concentric 13·6% vs. 8·4%) and composite events (eccentric: 17·6% vs. 5·4%; concentric: 18·6% vs. 12·7%) compared with nondilated LVH. While eccentric nondilated LVH had comparable risk for adverse outcomes compared with normal LV mass (all-cause death: relative risk (RR) 0·68, 95% confidential interval (CI) 0·25-1·85; composite events: RR 0·75, 95% CI 0·36-1·58). Cox regression analyses showed that eccentric dilated LVH had the highest propensity to all-cause death (adjusted hazard ratio [aHR] 2·752 [95% CI 1·749-4·328], P < 0·001) and composite events (aHR 2·462 [95% CI 1·688-3·592], P < 0·001).

CONCLUSION

In patients with CAD, dilated LVH and nondilated LVH provide distinct prognostic information. Eccentric nondilated LVH does not predict adverse outcomes.

Left ventricular hypertrophy patterns and incidence of heart failure with preserved versus reduced ejection fraction

Higher left ventricular (LV) mass, wall thickness, and internal dimension are associated with increased heart failure (HF) risk. Whether different LV hypertrophy patterns vary with respect to rates and types of HF incidence is unclear. In this study, 4,768 Framingham Heart Study participants (mean age 50 years, 56% women) were classified into 4 mutually exclusive LV hypertrophy pattern groups (normal, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy) using American Society of Echocardiography-recommended thresholds of echocardiographic LV mass indexed to body surface area and relative wall thickness, and these groups were related to HF incidence. Whether risk for HF types (HF with reduced ejection fraction [<45%] vs preserved ejection fraction [≥45%]) varied by hypertrophy pattern was then evaluated. On follow-up (mean 21 years), 458 participants (9.6%, 250 women) developed new-onset HF. The age- and gender-adjusted 20-year HF incidence increased from 6.96% in the normal left ventricle group to 8.67%, 13.38%, and 15.27% in the concentric remodeling, concentric hypertrophy, and eccentric hypertrophy groups, respectively. After adjustment for co-morbidities and incident myocardial infarction, LV hypertrophy patterns were associated with higher HF incidence relative to the normal left ventricle group (p = 0.0002); eccentric hypertrophy carried the greatest risk (hazard ratio [HR] 1.89, 95% confidence interval [CI] 1.41 to 2.54), followed by concentric hypertrophy (HR 1.40, 95% CI 1.04 to 1.87). Participants with eccentric hypertrophy had a higher propensity for HF with reduced ejection fraction (HR 2.23, 95% CI 1.48 to 3.37), whereas those with concentric hypertrophy were more prone to HF with preserved ejection fraction (HR 1.66, 95% CI 1.09 to 2.51). In conclusion, in this large community-based sample, HF risk varied by LV hypertrophy pattern, with eccentric and concentric hypertrophy predisposing to HF with reduced and preserved ejection fraction, respectively.

Relation of thoracic aortic distensibility to left ventricular area (from the Multi-Ethnic Study of Atherosclerosis [MESA])

Decreased arterial compliance is an early manifestation of adverse structural and functional changes within the vessel wall. Its correlation with left ventricular (LV) area on computed tomography, a marker of LV remodeling, has not been well demonstrated. The aim of this study was to test the hypothesis that decreasing aortic compliance and increasing arterial stiffness are independently associated with increased LV area. The study population consisted of 3,540 patients (mean age 61 ± 10 years, 46% men) from the Multi-Ethnic Study of Atherosclerosis (MESA) who underwent aortic distensibility (AD) assessment on magnetic resonance imaging and LV area measurement on computed tomography (adjusted to body surface area). Multivariate logistic regression was performed to assess the association between body surface area-normalized LV area >75th percentile and AD after adjusting for baseline clinical, historical, and imaging covariates. Mean LV area index was 2,153 cm(2), and mean AD was 1.84 × 10(3) mm Hg(-1). Subjects in the lowest AD quartile were older, with higher prevalence rates of hypertension, diabetes, and hypercholesterolemia (p <0.05 for all comparisons). Using multivariate linear regression adjusting for demographics, traditional risk factors, coronary artery calcium, and C-reactive protein, each SD decrease was associated with an 18-cm(2) increase in LV area. In addition, decreasing AD quartiles were independently associated with increasing LV area index, defined as >75th percentile. In conclusion, in this multiethnic cohort, reduced AD was associated with increased LV area. Longitudinal studies are needed to determine if decreased distensibility precedes and directly influences increased LV area.

Sensitivity and specificity of frequently used electrocardiographic criteria for left ventricular hypertrophy in patients with anterior wall myocardial infarction

Electrocardiographic left ventricular hypertrophy (LVH) strongly predicts mortality in patients with myocardial infarction (MI). However, the validity of LVH voltage criteria in this context has not been assessed. Reviewing the coded database of echocardiographic studies performed at one institution, we performed a retrospective analysis of 49 patients who had anterior akinesis on the echocardiogram and anterior wall MI on the electrocardiogram. Results showed that, compared with the sensitivities and specificities of the electrocardiographic voltage criteria in historical cohorts, Cornell criteria were less sensitive and specific for the diagnosis of LVH in patients with anterior wall MI. The sensitivity was reduced in the presence of an associated lateral wall MI, and the specificity was reduced in the absence of a lateral wall MI (overall sensitivity in case of anterior wall MI, with or without an associated lateral wall MI, 21% vs 41%, P = 0.049; overall specificity 84% vs 98%, P = 0.003). All criteria, except for S in V(1) + R in V(5) or V(6) >3.5 mV, had a significantly reduced specificity in the case of anterior wall MI not associated with lateral wall MI, and all criteria, except for R in V(6) > R in V(5), had reduced sensitivity in the presence of a lateral wall MI. In conclusion, anterior wall MI reduces the sensitivity and the specificity of the most commonly used LVH voltage criteria.

Usefulness of electrocardiographic and echocardiographic left ventricular hypertrophy to predict adverse events in patients with a first non-ST-elevation acute myocardial infarction

Left ventricular hypertrophy (LVH) portends a worse outcome after non-ST-elevation acute myocardial infarction (NSTEMI). However, its definition has varied and the incremental prognostic information provided by echocardiography has been unclear. Different electrocardiographic and echocardiographic criteria for LVH were compared for their ability to predict in-hospital complications in 451 consecutive patients with a first NSTEMI, 337 of whom had a reliable echocardiogram. Five to 8% had LVH using Sokolow-Lyon or Cornell (voltage or product) criteria on admission; 15%, using either electrocardiographic criteria; and 24%, using echocardiography. LVH predicted the occurrence of adverse events (death, reinfarction, or severe angina or heart failure), with the strongest association found for the Cornell product (50.0% vs 24.9% of patients meeting or not meeting this criterion had complications, respectively; p = 0.002). This association persisted after adjusting for baseline clinical predictors (odds ratio 2.52, 95% confidence interval 1.19 to 5.35), and considering echocardiographic LVH did not improve the prediction. LVH was more closely related to heart failure occurrence than to recurrent ischemic events. A progressive increase in the rate of complications was observed across quartiles of the components of all LVH criteria (17.1%, 23.7%, 31.7%, and 36.2% for Cornell product, respectively; p <0.001). In conclusion, LVH, especially an abnormal Cornell product, increased the risk of heart failure, but was weakly related to recurrent ischemia in patients with NSTEMI. Echocardiographic LVH did not appear to add prognostic information to the electrocardiogram. However, considering LVH criteria in a more quantitative manner may augment their ability to predict adverse events in this population.

Antecedent left ventricular mass and infarct size in ST-elevation myocardial infarction

BACKGROUND

Increased left ventricular mass index (LVMI) is associated with a greater incidence of acute myocardial infarction (AMI), but there are no data regarding its impact on infarct size.

OBJECTIVES

The objective of this study was to determine whether LVMI impacts on infarct size.

METHODS

We analyzed consecutive patients with a first ST-elevation AMI and successful reperfusion of the culprit artery who underwent an echocardiographic assessment of LVMI and regional wall motion score index (RWMSI) <72 hours post AMI.

RESULTS

Of the 165 patients (76.4% men) with a mean age of 61.0 +/- 13.9 years, 53.9% had anterior wall involvement and 59.3% had increased LVMI. There were no significant differences in baseline characteristics between patients with and without increased LVMI, except for a greater prevalence of hypertension among patients with increased LVMI (44.0% vs 22.4%, P < .001). The distributions of anterior wall AMI location and culprit artery involvement were similar between the groups. Patients with increased LVMI were more likely to present with single-vessel coronary artery disease (P = .04) and heart failure upon presentation (P = .03). There was no significant difference between patients with and without increased LVMI in peak creatine kinase (2106.8 +/- 1642.7 vs 2551.2 +/- 2357.4 U/L, P = .16) or RWMSI (1.62 +/- 0.44 vs 1.61 +/- 0.38, P = .91). In addition, no correlation was observed between LVMI as a continuous variable and RWMSI (r = 0.11, P = .18) or peak creatine kinase values (r = 0.02, P = .81).

CONCLUSIONS

Among patients with a first ST-elevation AMI and successful reperfusion, antecedent increased LVMI was fairly common and did not impact on infarct size.

Left ventricular hypertrophy in hypertension as a predictor of coronary events: relation to geometry

The present review examines epidemiological evidence for a relation of left ventricular hypertrophy with coronary heart disease, and mechanisms that may represent pathophysiological links between left ventricular hypertrophy and coronary events. Left ventricular hypertrophy has been demonstrated to be a powerful predictor of coronary heart disease, and when geometry is concentric the relation is even stronger. In addition to its association with risk factors for atherosclerosis and mechanisms that precipitate acute heart attacks, left ventricular hypertrophy also directly predisposes to and aggravates clinical presentation of coronary heart disease through a number of biological mechanisms. These include the following: increase in oxygen requirement related to left ventricular geometry; coronary hypertension, with endothelial dysfunction and reduced coronary reserve; diastolic dysfunction; and structural remodelling of myocardium and vascular bed. Some of these alterations are also worsened by underlying coronary heart disease, and can potentially be maintained by loop mechanisms. A recognizable stage of abnormal coronary haemodynamics in the context of left ventricular hypertrophy is probably that at which coronary reserve is impaired in the absence of any other sign of heart disease; in many circumstances, this may occur early in the disease process.