Left ventricular function and regression of left ventricular hypertrophy in essential hypertension

Physical activity and impaired left ventricular relaxation in middle aged adults

The aim of this study was to examine the relationship between physical activity level and impaired left ventricular (LV) relaxation in a large sample of apparently healthy men and women. We conducted a cross-sectional study in 57,449 adults who underwent echocardiography as part of a comprehensive health examination between March 2011 and December 2014. Physical activity level was assessed using the Korean version of the International Physical Activity Questionnaire Short Form. The presence of impaired LV relaxation was determined based on echocardiographic findings. Physical activity levels were inversely associated with the prevalence of impaired LV relaxation. The multivariable-adjusted odds ratios (95% confidence interval) for impaired LV relaxation comparing minimally active and health-enhancing physically active groups to the inactive group were 0.84 (0.77–0.91) and 0.64 (0.58–0.72), respectively (P for trend < 0.001). These associations were modified by sex (p for interaction <0.001), with the inverse association observed in men, but not in women. This study demonstrated an inverse linear association between physical activity level and impaired LV relaxation in a large sample of middle-aged Koreans independent of potential confounders. Our findings suggest that increasing physical activity may be independently important in reducing the risk of impaired LV relaxation.

Impact of left ventricular hypertrophy on long-term clinical outcomes in hypertensive patients who underwent successful percutaneous coronary intervention with drug-eluting stents

Left ventricular hypertrophy (LVH) is associated with increased risk for vascular events and mortality. This study investigated 8-year clinical outcomes of hypertensive patients with LVH who underwent percutaneous coronary intervention (PCI) with drug-eluting stents (DES) compared with hypertensive patients without LVH.A total of 1704 consecutive hypertensive patients who underwent PCI from 2004 to 2014 were enrolled. We classified them into either the LVH group (n = 406) or the control group (without LVH, n = 1298). LVH was defined by LV mass index > 115 g/m in men and > 95 g/m in women. After propensity score matched (PSM) analysis, 2 PSM groups (366 pairs, n = 732, c-statistic = 0.629) were generated.For up to 8 years, the LVH group showed a higher incidence of cardiac death (4.4% vs 1.2%, log-rank P = .023, hazard ratio: 3.371, 95% confidence interval: 1.109-10.25; P = .032) compared with the control group. However, there were no significant differences between the 2 groups in the incidence of total death, myocardial infarction, revascularization, and major adverse cardiac events up to 8 years.LVH in hypertensive patients who underwent successful PCI with DES was associated with higher incidence of cardiac death up to 8 years of follow-up. More careful managements and clinical follow-up are needed and treatment strategies should specifically focus to target prevention and reversal of LVH in hypertensive patients.

Relationship Between γ-Glutamyltransferase Levels and Left Ventricular Diastolic Dysfunction

BACKGROUND

The goal of this study was to examine the association of serum γ-glutamyltransferase (GGT) levels with left ventricular (LV) diastolic dysfunction and LV hypertrophy.Methods and Results:A cross-sectional study of 79,459 Korean men and women who underwent an echocardiography as part of a comprehensive health examination between March 2011 and December 2014. The presence of LV diastolic dysfunction and LV hypertrophy was determined using echocardiography. Of the subjects, 5,447 had LV diastolic dysfunction and 2,070 had LV hypertrophy. Both LV diastolic dysfunction and LV hypertrophy were associated with higher levels of serum GGT. Multivariable-adjusted odds ratios (95% confidence interval) for LV diastolic dysfunction comparing serum GGT quartiles 2-4 with quartile 1 were 1.25 (1.08-1.44), 1.65 (1.43-1.91) and 2.23 (1.92-2.58), respectively (P for trend <0.001). Multivariable-adjusted odds ratios (95% CI) for LV hypertrophy comparing serum GGT quartiles 2-4 with quartile 1 were 1.13 (0.94-1.36), 1.14 (0.93-1.40) and 1.33 (1.07-1.65), respectively (P for trend 0.01). These associations of serum GGT levels with LV diastolic dysfunction and LV hypertrophy were modified by age (P for interaction <0.05).

CONCLUSIONS

This study demonstrated a positive association between serum GGT levels and LV diastolic dysfunction and LV hypertrophy in a large cohort of middle-aged men and women independent of potential confounders.

The impact of left ventricular hypertrophy on early and long-term survival after coronary artery bypass grafting

BACKGROUND

Left ventricular hypertrophy (LVH) can itself contribute to increased rates of cardiovascular events. We sought to determine the impact of LVH on in-hospital and long-term mortality after coronary artery bypass grafting (CABG).

METHODS

Between 1992 and 2003, 4140 consecutive patients underwent CABG. Long-term survival data (mean follow-up 7.0 years) were obtained from the National Death Index. The impact of LVH on in-hospital mortality was determined by multivariate logistic regression analysis. Patients with and without LVH were compared by Cox proportional hazard models and risk-adjusted Kaplan-Meier curves.

RESULTS

There were 977 patients (23.6%) with LVH. Their mean EuroSCORE was 7.4 +/- 3.4 and there were 40 in-hospital deaths (4.1%) in this group. Multivariate logistic regression showed that patients with LVH had less elective operations, higher Canadian Cardiovascular Society Functional Class, more previous myocardial infarctions and higher percentages of 3-vessel disease, hypertension, current congestive heart failure, malignant ventricular arrhythmias, chronic obstructive pulmonary disease, calcified aorta, low ejection fraction, intravenous nitroglycerine, previous percutaneous coronary interventions and smoking. After adjustment for all available pre, intra and postoperative variables LVH was not an independent predictor for in-hospital mortality (OR 1.04, 95% CIs 0.60-1.81, P = 0.891). Risk-adjusted Kaplan-Meier survival curves showed decreased long-term survival in patients with LVH after the first 3 years (HR 1.24, 95% CIs 1.06-1.44, P = 0.006).

CONCLUSIONS

Patients with LVH showed similar in-hospital mortality when compared with patients without LVH. However, LVH was a detrimental risk factor for late mortality, especially after the third postoperative year. These data suggest the need for a more frequent long-term follow-up among patients with LVH undergoing CABG.

B-type natriuretic peptide and wall stress in dilated human heart

Background Although B-type natriuretic peptide (BNP) is used as complimentary diagnostic tool in patients with unknown thoracic disorders, many other factors appear to trigger its release. In particular, it remains unresolved to what extent cellular stretch or wall stress of the whole heart contributes to enhanced serum BNP concentration. Wall stress cannot be determined directly, but has to be calculated from wall volume, cavity volume and intraventricular pressure of the heart. The hypothesis was, therefore, addressed that wall stress as determined by cardiac magnetic resonance imaging (CMR) is the major determinant of serum BNP in patients with a varying degree of left ventricular dilatation or dysfunction (LVD). Methods A thick-walled sphere model based on volumetric analysis of the LV using CMR was compared with an echocardiography-based approach to calculate LV wall stress in 39 patients with LVD and 21 controls. Serum BNP was used as in vivo marker of a putatively raised wall stress. Nomograms of isostress lines were established to assess the extent of load reduction that is necessary to restore normal wall stress and related biochemical events. Results Both enddiastolic and endsystolic LV wall stress were correlated with the enddiastolic LV volume (r = 0.54, P < 0.001; r = 0.81, P < 0.001). LV enddiastolic wall stress was related to pulmonary pressure (capillary: r = 0.69, P < 0.001; artery: r = 0.67, P < 0.001). Although LV growth was correlated with the enddiastolic and endsystolic volume (r = 0.73, P < 0.001; r = 0.70, P < 0.001), patients with LVD exhibited increased LV wall stress indicating an inadequately enhanced LV growth. Both enddiastolic (P < 0.05) and endsystolic (P < 0.01) wall stress were increased in patients with increased BNP. In turn, BNP concentration was elevated in individuals with increased enddiastolic wall stress (>8 kPa: 587 +/- 648 pg/ml, P < 0.05; >12 kPa: 715 +/- 661 pg/ml, P < 0.001; normal < or =4 kPa: 124 +/- 203 pg/ml). Analysis of variance revealed LV enddiastolic wall stress as the only independent hemodynamic parameter influencing BNP (P < 0.01). Using nomograms with "isostress" curves, the extent of load reduction required for restoring normal LV wall stress was assessed. Compared with the CMR-based volumetric analysis for wall stress calculation, the echocardiography based approach underestimated LV wall stress particularly of dilated hearts. Conclusions In patients with LVD, serum BNP was increased over the whole range of stress values which were the only hemodynamic predictors. Cellular stretch appears to be a major trigger for BNP release. Biochemical mechanisms need to be explored which appear to operate over this wide range of wall stress values. It is concluded that the diagnostic use of BNP should primarily be directed to assess ventricular wall stress rather than the extent of functional ventricular impairment in LVD.

Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.

A new methodological approach to assess cardiac work by pressure-volume and stress-length relations in patients with aortic valve stenosis and dilated cardiomyopathy

In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.

Prognostic implications of left ventricular hypertrophy

BACKGROUND

To date there has been no comprehensive review of the association between left ventricular hypertrophy (LVH) at baseline and subsequent adverse clinical events.

METHODS

A total of 20 studies (with 48,545 participants) published between January 1960 and January 2000, identified through MEDLINE and other sources, related baseline electrocardiographic (ECG) or echocardiographic data on LVH to subsequent cardiovascular morbidity and all-cause mortality.

RESULTS

The prevalence of baseline LVH was higher in echocardiographic studies than in ECG studies (16%-74% vs 1%-44%, respectively). The adjusted risk of future cardiovascular morbidity associated with baseline LVH ranged from 1.5 to 3.5, with a weighted mean risk ratio of 2.3 for all studies combined. The adjusted risk of all-cause mortality associated with baseline LVH ranged from 1.5 to 8.0, with a weighted mean risk ratio of 2.5 for all studies combined. There was a trend toward a worse prognosis among women with baseline LVH compared with men. These findings persisted in the various population and ethnic groups studied.

CONCLUSION

With the exception of one study in dialysis patients, LVH consistently predicted high risk, independently of examined covariates, with no clear difference in relation to race, presence or absence of hypertension or coronary disease, or between clinical and epidemiologic samples. These results clarify the strong relation between LVH and adverse outcome and emphasize the clinical importance of its detection.

Effects of antihypertensive agents on the left ventricle: clinical implications

Hypertensive heart disease (HHD) is characterized by left ventricular hypertrophy (LVH), alterations of cardiac function, and coronary flow abnormalities. LVH is an independent cardiovascular risk factor related to cardiovascular complications in patients with hypertension. Therefore, a decrease in left ventricular mass is a therapeutic goal in these patients. The effect of the different antihypertensive agents on LVH regression has been studied in nearly 500 clinical trials. Most studies conclude that there is regression of LVH after significant decrease in blood pressure with most commonly prescribed antihypertensive agents. However, the ability to regress LVH is different between antihypertensive drug classes. ACE inhibitors and calcium channel antagonists are more potent in reducing left ventricular mass than beta-blockers, with diuretics falling in the intermediate group. Recent data suggest that angiotensin AT(1) receptor antagonists reduce left ventricular mass to a similar extent as ACE inibitors or calcium channel antagonists. Although a large number of studies have established that reversal of LVH decreases the occurrence of adverse cardiovascular events in patients with hypertension, the hypothesis that LVH regression is beneficial has not yet been conclusively proven. On the other hand, the time has come to revisit the current management of HHD simply focused on controlling blood pressure and reducing left ventricular mass. In fact, it is necessary to develop new approaches aimed to repair myocardial structure and protect myocardial perfusion and function and, in doing so, to reduce in a more effective manner, adverse risk associated with HHD. The identification of genes involved in both the process of HHD and the response to therapy may be critical for the development of these new approaches. This article will review briefly the available data on the effects of antihypertensive agents on HHD. In addition, the emerging new concepts on the pharmacology of hypertensive myocardial remodeling and the pharmacogenetic basis of the treatment of HHD will be also considered.

Determination of left ventricular mass by echocardiography in normotensive diabetic patients

Patients with Type 2 diabetes mellitus (DM) have excessive cardiovascular morbidity and mortality, even in the absence of hypertension. Left ventricular hypertrophy (LVH), which is an ominous prognostic sign and an independent risk factor for cardiac events, is often present in Type 2 DM patients. Forty-two Type 2 DM patients without hypertension, all of whom had been diagnosed more than 10 years ago, were examined in the present study. They had no evidence of renal dysfunction and had not received any anti-hypertensive drugs. Age-matched healthy normal subjects (n=47) were recruited as controls. All participants were classified according to the left ventricular mass index (LVMI) using M-mode echocardiography and their systolic function (fractional shortening) was examined. The systolic function was not significantly different between the Type 2 DM and control groups. LVH can be seen even in the normotensive Type 2 DM patients, with these patients still having a higher LVMI than the normal control subjects. Although the plasma insulin levels were not significantly increased in the Type 2 DM patients, the LVMI significantly correlated with plasma insulin levels. However, the LVMI did not significantly correlate with plasma fasting glucose and hemoglobin A1c in the Type 2 DM patients. These results suggest that LVH in Type 2 DM patients without hypertension may be associated with elevated plasma insulin levels.

Time course of regression of left ventricular hypertrophy after successful parathyroidectomy

BACKGROUND

We have shown that primary hyperparathyroidism may induce myocardial hypertrophy that is reversible after successful parathyroidectomy. The present study was designed to assess the time course of regression of left ventricular hypertrophy without further effects of drug treatment or disease states.

METHODS

We performed echocardiographic studies in 16 patients with primary hyperparathyroidism and normal resting blood pressure, normal systolic left ventricular function, no evidence of valvular disease, and without any current medication before parathyroidectomy, as well as during intermediate and long-term follow-up after successful parathyroidectomy.

RESULTS

Eleven patients (69%) had end-diastolic wall thickness of the interventicular septum and/or posterior wall greater than 11 mm on baseline echocardiogram. After surgical removal of the inciting disease and an average of 12.5 and 45.7 months of follow-up with normocalcemia and normal parathyroid hormone levels a prolonged regression of left ventricular hypertrophy was observed (interventricular septum, -0.68 mm at 12.5 months and -1.69 mm at 45.7 months; p = 0.02; posterior wall, -0.46 mm at 12.5 months and -2.24 mm at 45.7 months; p = 0.02).

CONCLUSIONS

We conclude that the removal of the cause of myocardial hypertrophy by successful parathyroidectomy leads to a prolonged reversal of hypertrophy. The progressive reduction of left ventricular wall thickness is not completed within 12 months.

Hypertensive left ventricular hypertrophy: pathophysiology, assessment and treatment

Left ventricular hypertrophy (LVH) is a strong predictor of cardiovascular morbidity and mortality. LVH is associated with coronary events, and there is an association between cerebrovascular disease and increased left ventricular mass (LVM). Experimental studies have elucidated the importance of non-myocytic cells inducing increased perivascular and interstitial fibrosis along with thickening of the media of intramyocardial coronary arteries in hypertensive LVH. M-mode echocardiography is the most accepted standard for the diagnosis and quantification of LVH, but some controversies exist regarding the ideal methodology for serial assessment of LVM. It is still a matter of debate whether 2-dimensional echo measurements represent a more accurate method. Hopefully, both the introduction of 3-dimensional echo and new Doppler techniques can provide more accurate measurements of LVM and additional information on changes in myocardial fibrosis and stiffness. Experimental studies have shown that normalization of hypertensive myocardial and coronary artery remodelling take place with drugs like angiotensin converting enzyme (ACE)-inhibitors and calcium antagonists. Two meta-analyses suggest that ACE-inhibitors may be the most efficient drugs in reducing LVM, but a clinical correlate to this assumption is at present not available. There are some indications that regression or progression of LVH assessed by ECG and echocardiography may in fact be related to the incidence of cardiovascular events. But large-scale controlled studies of various treatment regimens are still needed to establish whether drug induced regression can improve the prognosis of hypertensive LVH independent of the antihypertensive effect.

Should echocardiography be performed to assess effects of antihypertensive therapy? Test-retest reliability of echocardiography for measurement of left ventricular mass and function

OBJECTIVES

The purpose of this study was to determine the test-retest stability of echocardiography for the measurement of left ventricular mass and function in patients with hypertension.

BACKGROUND

Determination of changes in left ventricular mass may be impaired by study variability. The amount by which variables of mass and left ventricular function must change in an individual patient to exceed temporal variability has not been determined in a multicenter trial.

METHODS

Ninety-six patients with hypertension had two-dimensional targeted, M-mode Doppler echocardiography repeated at 6 +/- 8 days by the same technician utilizing the same machine. Left ventricular mass and variables of systolic and diastolic function were measured. Test-retest reliability and the width of the 95% confidence intervals of variable change, as well as the contributions of age, study quality and body size to measurement reliability, were determined.

RESULTS

Despite excellent reliability (intraclass coefficient of correlation 0.86), the 95% confidence interval width of a single replicate measurement of left ventricular mass was 59g, exceeding usual decreases in mass during treatment. Study quality, which was dependent on age and weight, influenced test reliability. Although the confidence interval width for ejection fraction was narrow (5 U), those for peak early (E) and late (A) diastolic velocities were wide, resulting in a confidence interval width for the E/A ratio of 1.5.

CONCLUSIONS

The temporal variability, particularly in obese or elderly patients, or both, of echocardiography for measurement of left ventricular mass precludes its use to measure changes in mass of the magnitude likely to occur with therapy. Measurement stability is affected by study quality, and age and body weight both influence study quality. Although ejection fraction shows little temporal variability, the large width of the confidence interval of the Doppler E/A ratio impairs its use to serially measure diastolic function.