Heart failure following cancer treatment: characteristics, survival and mortality of a linked health data analysis.

BACKGROUND: Cardiotoxicity resulting in heart failure is a devastating complication of cancer therapy. A patient may survive cancer only to develop heart failure (HF), which has a higher mortality rate than some cancers. AIM: This study aimed to describe the characteristics and outcomes of HF in patients with blood or breast cancer after chemotherapy treatment. METHODS: Queensland Cancer Registry, Death Registry and Hospital Administration records were linked (1996-2009). Patients were categorised as those with an index HF admission (that occurred after cancer diagnosis) and those without an index HF admission (non-HF). RESULTS: A total of 15 987 patients was included, and 1062 (6.6%) had an index HF admission. Median age of HF patients was 67 years (interquartile range 58-75) versus 54 years (interquartile range 44-64) for non-HF patients. More men than women developed HF (48.6% vs 29.5%), and a greater proportion in the HF group had haematological cancer (83.1%) compared with breast cancer (16.9%). After covariate adjustment, HF patients had increased mortality risk compared with non-HF patients (hazard ratios 1.67 (95% confidence interval, 1.54-1.81)), and 47% of the index HF admission occurred within 1 year from cancer diagnosis and 70% within 3 years. CONCLUSION: Cancer treatment may place patients at a greater risk of developing HF. The onset of HF occurred soon after chemotherapy, and those who developed HF had a greater mortality risk.

Individualized compared with conventional dosing of enoxaparin.

The aim of this study was to compare an individualized dosing regimen for enoxaparin to conventional dosing. Patients in the individualized arm were initially dosed according to weight: patients <100 kg using total body weight; patients >/=100 kg using lean body weight. Doses were adjusted at 48 h according to renal function. Patients in the conventional arm received enoxaparin according to current practice. Dose-individualized patients had fewer bleeding events (primary end point; relative risk (RR)=0.12, 95% confidence interval (CI)=0.01-0.89, P=0.03) and composite bleeding and bruising events (secondary end point; RR=0.30, 95% CI=0.12-0.71, P=0.003) than those who received conventional dosing. In both arms of the study, there were no recurrent thromboembolic events during treatment and no deaths had occurred at 30 days. Dose individualization of enoxaparin significantly reduces the prevalence of bleeding and bruising events, without apparent loss in effectiveness.

High-resolution magnification endoscopy can reliably identify normal gastric mucosa, Helicobacter pylori-associated gastritis, and gastric atrophy.

BACKGROUND AND STUDY AIMS: The aims of the study were to describe the magnified endoscopic findings in the gastric body, correlate these with histology, and evaluate their reproducibility in the assessment of the magnified endoscopic patterns seen. PATIENTS AND METHODS: A total of 95 consecutive dyspeptic patients underwent upper gastrointestinal endoscopy with a magnifying endoscope. The endoscopists classified the magnified endoscopic patterns and correlated them with the histological findings. In the second part of the study, 200 images were shown to five endoscopists in order to examine inter- and intraobserver variability in image assessment. RESULTS: The magnified endoscopic findings in the gastric body were categorized into four types: type 1, honeycomb-type subepithelial capillary network (SECN) with regular arrangement of collecting venules and regular, round pits; type 2, honeycomb-type SECN with regular, round pits, but loss of collecting venules; type 3, loss of normal SECN and collecting venules, with enlarged white pits surrounded by erythema; and type 4, loss of normal SECN and round pits, with irregular arrangement of collecting venules. The sensitivity, specificity, and positive and negative predictive values of the type 1 pattern for predicting normal gastric mucosa were 92.7% (95% confidence interval [CI] 93.2-97.3%), 100% (95% CI 83.9-100%), 100% (95% CI 92.9-100%), and 83.8% (95% CI 65.5-93.9%). The sensitivity, specificity, and positive and negative predictive values of types 2 and 3 patterns for predicting a Helicobacter pylori-infected stomach were 100% (95% CI 83.9-100%), 92.7% (95% CI 93.2-97.3%), 83.8% (95% CI 65.5-93.9%), and 100% (95% CI 92.9-100%). The sensitivity, specificity, and positive and negative predictive values of a type 4 pattern for predicting gastric atrophy were 90% (95% CI 66.8-98.2%), 96% (95% CI 87.9-98.9%), 85.7% (95% CI 62.6-96.2%), and 97.3% (95% CI 89.6-99.5%. The kappa values for inter- and intraobserver agreement in predicting normal gastric mucosa, H. pylori gastritis, and gastric atrophy were 0.864 and 0.913 respectively. CONCLUSION: High-resolution magnification endoscopy can reliably identify the normal gastric mucosa, H. pylori-associated gastritis, and gastric atrophy in a Western population.

Ventricular interaction and external constraint account for decreased stroke work during volume loading in CHF.

The slope of the stroke work (SW)-pulmonary capillary wedge pressure (PCWP) relation may be negative in congestive heart failure (CHF), implying decreased contractility based on the premise that PCWP is simply related to left ventricular (LV) end-diastolic volume. We hypothesized that the negative slope is explained by decreased transmural LV end-diastolic pressure (LVEDP), despite the increased LVEDP, and that contractility remains unchanged. Rapid pacing produced CHF in six dogs. Hemodynamic and dimension changes were then measured under anesthesia during volume manipulation. Volume loading increased pericardial pressure and LVEDP but decreased transmural LVEDP and SW. Right ventricular diameter increased and septum-to-LV free wall diameter decreased. Although the slopes of the SW-LVEDP relations were negative, the SW-transmural LVEDP relations remained positive, indicating unchanged contractility. Similarly, the SW-segment length relations suggested unchanged contractility. Pressure surrounding the LV must be subtracted from LVEDP to calculate transmural LVEDP accurately. When this was done in this model, the apparent decrease in contractility was no longer evident. Despite the increased LVEDP during volume loading, transmural LVEDP and therefore SW decreased and contractility remained unchanged.

Endothelium-derived nitric oxide contributes to the regulation of venous tone in humans.

BACKGROUND: Although nitric oxide (NO) is known to play an important part in the regulation of arterial tone, little is known about its role in veins. The aim of this study was to investigate the role of basal and stimulated NO activity in the regulation of tone of the human venous capacitance bed. METHODS AND RESULTS: We measured venous tone using radionuclide forearm venous plethysmography in 24 healthy subjects with no cardiovascular risk factors. In 13 subjects, basal NO activity was assessed by measuring the effects on venous tone of an intra-arterial infusion of the NO synthase inhibitor N-monomethyl-L-arginine (L-NMMA). In the remaining 11 subjects, stimulated NO activity was evaluated by measuring the effects of an intra-arterial infusion of incremental doses of carbachol, followed in a subgroup by coinfusion with L-NMMA. Infusion of carbachol caused dose-dependent venodilation, with a maximal reduction in forearm venous tone of 40.1+/-12.5% (P<0.0001). Carbachol-induced venodilation was inhibited by L-NMMA (48.9+/-6.2% reversal of maximal venodilation, P<0.01). Infusion of L-NMMA alone caused venoconstriction (9.1+/-6.4% increase in venous tone, P=0.002). CONCLUSIONS: Human forearm capacitance veins exhibit both stimulated and basal NO activity, which indicates that NO contributes not only to the regulation of venous tone but also to resting venous tone in healthy human subjects.

The role of diastolic ventricular interaction in abnormal cardiac baroreflex function in chronic heart failure.

Baroreflex abnormalities have been well documented in both patients with chronic heart failure and experimental animal models of heart failure. These abnormalities are associated with increased mortality and probably contribute to neurohumoral activation. While it is likely that several mechanisms contribute to reduced baroreflex sensitivity, it has been difficult to explain why baroreflex control mechanisms during acute volume unloading in patients with severe chronic heart failure should be directionally opposite to those in normal subjects. Volume unloading normally causes a reduction in baroreceptor activity, and hence an increase in sympathetic outflow; however, patients with chronic heart failure develop attenuated increases or paradoxical reductions in forearm vascular resistance, muscle sympathetic nerve activity, and noradrenaline spillover. It has been suggested that this probably represents paradoxical activation of left ventricular (LV) mechanoreceptors, but why LV receptors should behave in such a fashion has not been determined. In the setting of diastolic ventricular interaction, the filling of the left ventricle is constrained by the surrounding pericardium and right ventricle. In these patients, the reduction in right ventricular (RV) volume that normally occurs during acute volume unloading allows for an increase in LV end-diastolic volume (as opposed to the reduction in LV volume that normally occurs). We have demonstrated this to be important in some patients with chronic heart failure, and observed that baroreflex control of forearm vascular resistance was markedly impaired in these patients. We propose that the increase in LV volume that occurred during volume unloading would increase LV mechanoreceptor activity, and could therefore explain the paradoxical reductions in sympathetic outflow. As discussed, this has important therapeutic implications.

Restrictive left ventricular filling patterns are predictive of diastolic ventricular interaction in chronic heart failure.

OBJECTIVES: The purpose of this study was to determine whether restrictive left ventricular (LV) filling patterns are associated with diastolic ventricular interaction in patients with chronic heart failure. BACKGROUND: We recently demonstrated a diastolic ventricular interaction in approximately 50% of a series of patients with chronic heart failure, as evidenced by paradoxic increases in LV end-diastolic volume despite reductions in right ventricular end-diastolic volume during volume unloading achieved by lower body negative pressure (LBNP). We reasoned that such an interaction would impede LV filling in mid and late diastole, but would be minimal in early diastole, resulting in a restrictive LV filling pattern. METHODS: Transmitral flow was assessed using pulsed wave Doppler echocardiography in 30 patients with chronic heart failure and an LV ejection fraction < or = 35%. Peak early (E) and atrial (A) filling velocities and E wave deceleration time were measured. Left ventricular end-diastolic volume was measured using radionuclide ventriculography before and during -30-mm Hg LBNP. RESULTS: Nine of the 11 patients with and 2 of the 16 patients without restrictive LV filling patterns (E/A > 2 or E/A 1 to 2 and E wave deceleration time < or = 140 ms) increased LV end-diastolic volume during LBNP (p = 0.001). The change in LV end-diastolic volume during LBNP was correlated with the baseline A wave velocity (r = -0.52, p = 0.005) and E/A ratio (r = 0.50, p = 0.01). CONCLUSIONS: Restrictive LV filling patterns are associated with diastolic ventricular interaction in patients with chronic heart failure. Volume unloading in the setting of diastolic ventricular interaction allows for increased LV filling. Identifying patients with chronic heart failure and restrictive filling patterns may therefore indicate a group likely to benefit from additional vasodilator therapy.

Diastolic ventricular interaction in chronic heart failure: relation to heart rate variability and neurohumoral status.

It is likely that abnormal baroreflex control mechanisms are at least partially responsible for autonomic dysfunction in chronic heart failure. We recently demonstrated that diastolic ventricular interaction is associated with impaired baroreflex control of vascular resistance in heart failure. We reasoned that by constraining left ventricular filling, such interaction would decrease baroreflex activity and, thereby, increase sympathetic and decrease parasympathetic outflow. We hypothesized, therefore, that diastolic ventricular interaction in chronic heart failure patients would be associated with autonomic dysfunction. We used radionuclide ventriculography to measure changes in left and right ventricular end-diastolic volumes during acute volume unloading achieved by -30 mm Hg lower-body negative pressure in 30 patients with chronic heart failure. An increase in left ventricular volume in association with a reduction in right ventricular volume indicates diastolic ventricular interaction (a larger increase indicating a greater degree of interaction). We also measured heart rate variability (n = 23) and resting venous plasma norepinephrine (n = 24), epinephrine (n = 24), and atrial natriuretic peptide (ANP) (n = 14). During lower-body negative pressure, while right ventricular volume decreased in all patients (P < 0.001), left ventricular end-diastolic volume increased (from 152 +/- 25 to 157 +/- 36 ml/m2, P = 0.01). The change in left ventricular volume was positively correlated with resting plasma norepinephrine (P < 0.01) and ANP (P < 0.005), and negatively correlated with the standard deviation of normal to normal R-R intervals (P < 0.005), the root-mean-square of differences between successive normal to normal R-R intervals (P < 0.05), total power (P < 0.01), low-frequency power (P < 0.01), and high-frequency power (P < 0.05). Diastolic ventricular interaction in patients with chronic heart failure is associated with sympathetic nervous system activation evidenced by increased plasma norepinephrine and reduced heart rate variability.

Forearm vasoconstriction during dynamic leg exercise in patients with chronic heart failure.

Previous studies assessing vascular responses in nonexercising beds during exercise in patients with chronic heart failure (CHF) have yielded varying results. We proposed that the clinical and hemodynamic severity of heart failure may explain some of the variation. We reasoned that diastolic ventricular interaction (DVI), by limiting the ability of such patients to increase left ventricular (LV) volume and stroke volume during exercise, would attenuate baroreflex activation, resulting in increased sympathetic activation and hence exaggerated vasoconstriction. We hypothesized therefore that vasoconstriction in nonexercising beds would be exaggerated in patients with symptomatic and hemodynamically severe heart failure, particularly if associated with DVI. We measured forearm vascular resistance (FVR) during semierect cycle exercise in 22 CHF patients and 23 control subjects. DVI was assessed by measuring changes in ventricular volumes (radionuclide ventriculography) during volume unloading (-30 mm Hg lower-body negative pressure) in the heart failure patients and was inferred when LV end-diastolic volume paradoxically increased. Patients with symptoms of heart failure developed larger increases in FVR during exercise than did asymptomatic patients. There were significant correlations between the change in FVR during peak exercise and the resting mean pulmonary arterial pressure and pulmonary vascular resistance. CHF patients with DVI developed exaggerated increases in FVR (median [25th to 75th percentile]) compared with the remaining patients during low-workload exercise (138 [66 to 171] vs 6.4 [-4.3 to 28] units, P = 0.002) and during peak exercise (160 [90 to 384] vs 61 [-7.4 to 75] units, P < 0.02). Vasoconstriction in nonexercising beds is exaggerated in CHF patients with clinically and hemodynamically severe heart failure, particularly if associated with DVI. This may explain some of the reported variation in the degree of sympathetic activation that occurs during exercise in CHF patients.

Diastolic ventricular interaction in chronic heart failure.

BACKGROUND: Diastolic ventricular interaction describes a situation in which the volume of one ventricle is directly influenced by the volume of the other ventricle. Such interaction is normally negligible, but it is accentuated in circumstances associated with pulmonary hypertension and volume overload. When this interaction occurs, acute volume unloading results in a reduction in right ventricular end-diastolic volume, as expected, but left ventricular end-diastolic volume paradoxically increases. Since chronic heart failure is a volume-overloaded state associated with pulmonary hypertension, we hypothesised that this interaction may be clinically important in patients with heart failure. METHODS: A radionuclide technique incorporating cardiac scintigraphy was used to measure the effect of acute volume unloading, achieved by 30 mm Hg lower-body suction, on right and left ventricular end-diastolic volumes in 21 patients with chronic heart failure and 12 healthy individuals (controls). FINDINGS: In nine heart-failure patients, there was a paradoxical increase in left ventricular end-diastolic volume in association with an expected decrease in right ventricular end-diastolic volume during lower-body suction. This response was not seen in the control group. The mean change in left ventricular end-diastolic volume differed significantly between the heart-failure patients and controls (6 [SD 19] vs -19 [12] mL, p = 0.0003). However, the change in right ventricular end-diastolic volume was similar in the two groups (-18 [11] vs -20 [8]%. p = 0.70). Patients who increased left ventricular end-diastolic volume during lower-body suction had higher resting pulmonary arterial and pulmonary capillary wedge pressures than the remaining heart-failure patients. INTERPRETATION: The response of nine patients in our study suggests diastolic ventricular interaction, which we believe could be common in patients with chronic heart failure. This finding is relevant to their management, since it emphasises the importance of venodilator therapy. The relation between stroke volume and left ventricular end-diastolic volume, by the Frank-Starting law of the heart, may explain why some patients with chronic heart failure paradoxically increase stroke volume when pulmonary capillary wedge pressure is lowered with vasodilators.

Diastolic ventricular interaction: a possible mechanism for abnormal vascular responses during volume unloading in heart failure.

BACKGROUND: Baroreflex dysfunction is common in chronic heart failure and contributes to the associated sympathoexcitation. Baroreceptor activity normally decreases during volume unloading, causing an increase in sympathetic outflow and resulting in forearm vasoconstriction. Some heart failure patients develop attenuated vasoconstriction or paradoxical vasodilation. The mechanism for this is unknown. We have recently demonstrated diastolic ventricular interaction in some patients with chronic heart failure as evidenced by increases in left ventricular (LV) end-diastolic volume in association with decreases in right ventricular (RV) volume during volume unloading. We reasoned that such an increase in LV volume, by increasing LV mechanoreceptor activity, would decrease sympathetic outflow and could therefore explain the abnormal vascular responses seen in such patients. METHODS AND RESULTS: We assessed changes in forearm vascular resistance (FVR) during application of -20 and -30 mm Hg lower-body negative pressure (LBNP) in 24 patients with chronic heart failure and 16 control subjects. Changes in LV and RV end-diastolic volumes were assessed during -30 mm Hg LBNP in all heart failure patients. Diastolic ventricular interaction was demonstrated in 12 patients as evidenced by increases in LV end-diastolic volume in association with decreases in RV end-diastolic volume during LBNP. Changes in FVR during LBNP (-20 and -30 mm Hg) were markedly attenuated in these 12 patients (-1.6+/-11.2 and -0.9+/-12.5 U) compared with both the remaining patients (11.9+/-10.0 and 17.0+/-12.3 U) and the control subjects (16.5+/-9.5 and 23.1+/-13.9 U) (P<.01 for both comparisons at each level of LBNP). FVR decreased in 5 of these 12 patients during -30 mm Hg LBNP, a response seen in none of the remaining patients (P=.01). CONCLUSIONS: Diastolic ventricular interaction in patients with chronic heart failure is associated with attenuated forearm vasoconstriction or paradoxical vasodilation during LBNP. This may explain the apparent derangement in baroreflex control of sympathetic outflow during acute volume unloading in heart failure.

Demonstration of late cardiotoxicity following bone marrow transplantation by assessment of exercise diastolic filling characteristics.

We evaluated the role of rest and exercise left ventricular diastolic filling parameters as a marker of cardiotoxicity in 25 consecutive patients 1 year following BMT. Ten age- and sex-matched subjects served as controls. Patients were evaluated in toto and in three sub-groups according to chemotherapy. Left ventricular ejection fraction (EF), peak filling rate (PFR) and time to peak filling (TTPF) were assessed at rest and at peak exercise. EF and PFR were similar at rest and at peak exercise in patients and controls. TTPF was significantly prolonged at rest in patients compared to controls (200 +/- 65 vs 131 +/- 26 ms, P = 0.003) and at peak exercise was markedly longer in patients (142 +/- 40 vs 54 +/- 19 ms, P < 0.001). Sub-group analysis demonstrated abnormal resting TTPF in those patients who had received either combination anthracycline and CY or anthracycline and melphalan, while those patients who received CY alone had normal resting TTPF. However, exercise TTPF was abnormally prolonged in all patient groups. While all controls demonstrated a normal decrease in TTPF during exercise, four of the 25 patients had a paradoxical increase in TTPF during exercise. Exercise diastolic function may provide evidence of cardiotoxicity in long-term survivors of BMT.

Failure of reflex venoconstriction during exercise in patients with vasovagal syncope.

BACKGROUND: In this study, we tested two hypotheses. First, we tested the hypothesis that reflex constriction of the venous capacitance beds in patients with vasovagal syncope is impaired during both subhypotensive lower-body negative pressure. Second, we proposed that splenic venoconstriction may be impaired during exercise in patients with vasovagal syncope. METHODS AND RESULTS: We evaluated 25 patients with vasovagal syncope (age, 45.0 +/- 15.9 years; 12 men, 13 women) and 24 control subjects (age, 41.3 +/- 13.7 years; 16 men, 8 women). A nuclear technique was used to assess changes in forearm venous tone during lower-body negative pressure and in splenic venous volume during cycle exercise. Changes in forearm vascular resistance (FVR) during cycle exercise were assessed with a strain-gauge plethysmography technique. The percentage reduction in unstressed forearm vascular volume during lower-body negative pressure was similar in patients and control subjects (9.0 +/- 8.0% versus 9.7 +/- 5.9%, P=NS). During exercise, splenic venous volume decreased less in patients than in control subjects (15.8 +/- 21.7% versus 42.6 +/- 12.6%, P < .0001). FVR decreased by 2 +/- 32% in patients but increased 108 +/- 90% in control subjects (P < .0001). There was no relation between percentage change in splenic volume and percentage change in FVR during exercise in either patients or control subjects (r= -.06, P=NS and r= -.18, P=NS, respectively). CONCLUSIONS: Patients with vasovagal syncope exhibit a failure of the normal increase in tone in the splenic capacitance bed and in forearm resistance vessels during dynamic exercise. Forearm venous tone increases normally during lower-body negative pressure.

Abnormal forearm vascular responses during dynamic leg exercise in patients with vasovagal syncope.

BACKGROUND: We have reported previously that in some patients with normal hearts who present with exercise syncope, abnormal forearm vasodilation is seen during leg exercise and tilt table tests are positive. This suggests that exercise syncope may be a variant of vasovagal syncope. In this study we tested the hypothesis that there is loss of the normal forearm vasoconstrictor response during dynamic leg exercise in an unselected population of patients with classic vasovagal syncope. METHODS AND RESULTS: We evaluated forearm vascular responses during maximal semierect cycle exercise in 28 consecutive patients with vasovagal syncope and compared them with 30 age-matched control subjects. We also evaluated blood pressure responses during erect treadmill exercise (Bruce protocol). While forearm vascular resistance at rest was similar in the patients with vasovagal syncope and the control group, forearm vascular resistance was markedly lower in the patients than in control subjects at peak exercise (85 +/- 54 versus 149 +/- 94 units, P = .002). Forearm vascular resistance fell by 3 +/- 48% during exercise in patients versus an increase of 135 +/- 103% in control subjects (P < .0001). Systolic blood pressure during erect exercise was lower in patients versus control subjects (155 +/- 32 versus 188 +/- 17 mm Hg, P < .0001). Six of the vasovagal patients complained of exercise syncope or presyncope on specific inquiry, and 4 of these 6 exhibited exercise hypotension during erect treadmill exercise testing. CONCLUSIONS: Patients with vasovagal syncope exhibit a failure of the normal vasoconstrictor response in the forearm during dynamic leg exercise. Exercise syncope and presyncope are not uncommon in unselected patients with classic vasovagal syncope, as is exercise hypotension.