6075Workload adjusted blood pressure response rather than peak systolic blood pressure is associated with increased all-cause mortality in males; results from 7097 treadmill exercise tests

Background

Systolic blood pressure (SBP) is routinely measured during exercise testing (ET) and is in part determined by cardiac output and peripheral vascular resistance. A frequently used threshold for defining hypertensive response to exercise is ≥210 mmHg but this does not account for the fact that SBP is related to workload, via cardiac output.

Purpose

To examine the prognostic implications of considering external workload (METs) adjusted SBP response to exercise.

Methods

We reviewed all symptom-limited treadmill ET in males between 1987 and 2007 at a single centre (inclusion/exclusion criteria detailed in figure 1A). SBP was measured standing at rest and at peak exercise. Workload adjusted BP response with exercise (SBP/MET slope) was calculated as ΔSBP/ΔMET. METs were calculated from peak speed and grade according to the standard American College of Sports Medicine (ACSM) formula. Age-predicted peak METs was calculated as: 18 - 0.15 × age. Ten-year Cox proportional hazard ratios (HR) with 95% confidence intervals were calculated and adjusted as outlined in figure 1B.

Results

7097 subjects were included, of which 1559 (22%) died within 10 years. Survivors were younger (57.2±10.6 y vs. 64.5±10.3 y, p<0.001) and reached higher % of age-predicted METs (97±33% vs. 82±33%, p<0.001). Survivors had higher peak SBP (181±26 vs. 176±27 mmHg, p<0.001) as well as greater ΔSBP (49±22 vs. 42±22 mmHg, p<0.001), while they had lower SBP/MET slope (7.0±4.4 vs. 8.9±6.5 mmHg/MET, p<0.001). A peak SBP ≥210 mmHg was associated with better survival; 10-yr adjusted HR: 0.76 (0.64–0.88, p<0.001). In contrast, a higher SBP/MET slope was associated with increased mortality (table 1).

Table 1. Ten year adjusted hazard ratios Variable HR (95% CI) P Variable HR (95% CI) P Variable HR (95% CI) P Peak SBP, Q1: 100–159 mmHg REF REF Delta SBP, Q1: 1–29 mmHg REF REF SBP/MET slope, Q1: 0.2–4.2 REF REF Peak SBP, Q2: 160–179 mmHg 0.81 (0.71–0.94) 0.006 Delta SBP, Q2: 30–46 mmHg 0.80 (0.70–0.91) 0.001 SBP/MET slope, Q2: 4.3–6.2 0.95 (0.81–1.12) 0.562 Peak SBP, Q3: 180–199 mmHg 0.68 (0.58–0.78) <0.001 Delta SBP, Q3: 47–61 mmHg 0.76 (0.66–0.88) <0.001 SBP/MET slope, Q3: 6.2–9.1 1.18 (1.01–1.37) 0.032 Peak SBP, Q4: ≥200 mmHg 0.60 (0.51–0.69) <0.001 Delta SBP, Q4: ≥62 mmHg 0.59 (0.50–0.69) <0.001 SBP/MET slope, Q4: ≥9.1 1.40 (1.22– 1.62) <0.001 HR, hazard ratio (adjusted according to figure 1B); SBP, systolic blood pressure; MET, metabolic equivalent of task; Q1–Q4, quartiles (Q1 as reference).

Figure 1

Conclusion

Workload adjusted blood pressure response to exercise in contrast to peak BP response was associated with increased mortality in male patients referred for ET. Of note, reaching a BP of at least 210 mmHg (suggested to define a hypertensive response to exercise) was associated with a 24% reduction in all-cause mortality.

Acknowledgement/Funding

K Hedman was supported by post-doc. grants from the Fulbright Commission, the Swedish Society of Medicine, County Council of Östergötland, Sweden

Abstract P3-14-02: Incidence of venous thromboembolism in patients with hormone receptor-positive HER2-negative metastatic breast cancer treated with CDK 4/6 inhibitors: A systematic review and meta- analysis of randomized controlled trials

Background:

The cyclin dependent kinases (CDK) along with their partners, the cyclins, have a crucial role in regulation of the cell cycle. Several CDK-targeted agents have been employed in hormone receptor positive metastatic breast cancer (MBC) with noteworthy safety concerns. Nevertheless, the impact of this agent on risk of venous thromboembolism (VTE) remains uncertain. We performed a systematic review and meta-analysis of randomized controlled trials (RCT) to determine the risk of VTE among patients with hormone receptor-positive HER2-negative MBC treated with CDK 4/6 inhibitors.

Methods:

We systematically conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts through June 2017. Trials that mention deep vein thrombosis and pulmonary embolism as adverse effects were incorporated in the analysis. The primary meta- analytic approach was a fixed effects model using the Mantel-Haenszel (MH) method. It was used to calculate the estimated pooled risk ratio (RR), and risk difference (RD) with 95% confidence interval (CI). Pooled VTE rates were estimated as follows: we multiplied the median follow-up duration by the sample size. Crude study-specific VTE rates were then calculated by dividing the number of incident VTE cases by the total number of person-months follow-up.

Results:

A total of 2671 patients with hormone receptor-positive HER2-negative MBC from four phase 3 studies and one phase 2 study were eligible for analysis. The study arm used palbociclib-letrozole, palbociclib-fulvestrant, ribociclib-letrozole and abemaciclib-fulvestrant while the control arm utilized placebo in combination with letrozole or fulvestrant. The I2 statistic for heterogeneity was 13.6, and the heterogeneity X2 (Cochran's Q) was 4.6 (P= 0.3), suggesting homogeneity of results among the randomized trials. The VTE incidence was 24 (1.46%) in CDK 4/6 group vs 4 (0.39%) in control group. The pooled RR for VTE was 2.736 (95% CI: 1.115 – 6.714, P = 0.028) and the absolute RD was 0.010 (95% CI: 0.002 – 0.018, P = 0.010) according to the fixed effects model. By the random effects model, the pooled RR was 2.411 (95% CI: 0.809 – 7.181, P = 0.114) and RD was 0.009 (95% CI: 0.0 – 0.019, P = 0.048). Over median follow up of 36 months, the RR for VTE was 3.792 (95% CI: 1.838 – 7.822, P &lt; 0.0001) and RD was 0.024 (95% CI: 0.014 – 0.034, P &lt; 0.0001) with the fixed effects model. By the random effects model, the pooled RR for VTE was 4.248 (95% CI: 0.952- 18.959, P = 0.058) and RD was 0.026 (95% CI: 0.004 – 0.021, P &lt; 0.0001). The pooled rate of VTE among CDK 4/6 group was 2.99 per person years compared to 0.50 per person years among control arm.

Conclusion:

Approximately 1% of patients on letrozole or fulvestrant alone developed VTE in previous studies. Our meta-analysis demonstrated that the addition of CDK 4/6 inhibitors to letrozole or fulvestrant, contribute to higher incidence of VTE. More randomized trials are required to determine the actual relation and definitive incidence of VTE, a major cause of morbidity and mortality among these patients.

Citation Format: Thein KZ, Zaw MH, Tun AM, Jones C, Radhi S, Hardwicke F, Oo TH. Incidence of venous thromboembolism in patients with hormone receptor-positive HER2-negative metastatic breast cancer treated with CDK 4/6 inhibitors: A systematic review and meta- analysis of randomized controlled trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-14-02.

Smokeless tobacco use in Myanmar

Smokeless tobacco (SLT) use in various forms is highly prevalent in Myanmar. The aim of this paper is to study the socio-cultural background of SLT use and products of SLT in Myanmar and the prevalence of SLT based on surveys and from other published data bases. Information was obtained from the literature review and through search on PubMed and Google. The use of SLT is deep rooted in Myanmar culture, and there is also wide-spread belief that it is not as dangerous as smoking. SLT use is growing in Myanmar. About 9.8% of the 13-15-year-old school children and 20.8% adults use SLT; it is many-fold higher among men. The use of SLT is prevalent using many different types of tobacco and forms of its use in Myanmar. The socio-cultural acceptance and the myths were compounded by the lack of specific SLT control component in the National Tobacco Control Legislation adopted needs to be addressed as a priority through intensified community awareness programs, public education programs, and advocacy campaigns. Effective enforcement of the law and amendment to include specific components of SLT in the provisions of the law is highly recommended. The prevalence of SLT is high among school children and adults (especially in men) in Myanmar. Betel quid and tobacco is a common form of SLT use. Although control of smoking and consumption of tobacco product law exists, its implementation is weak.

Prognostic value of serum cardiac troponin I in ambulatory patients with chronic renal failure undergoing long-term hemodialysis: a two-year outcome analysis

OBJECTIVES

We sought to evaluate the prognostic value of cardiac troponin I (cTnI) in asymptomatic, ambulatory patients with chronic renal failure treated with long-term hemodialysis.

BACKGROUND

Smaller, short-term follow-up studies on this subject have given conflicting results.

METHODS

A total of 126 ambulatory patients with chronic renal failure treated with long-term hemodialysis were followed for two years for all-cause mortality, cardiac mortality, all-cause hospital admissions and cardiac hospital admissions. Serum cTnI was measured before dialysis at the time of study entry.

RESULTS

One hundred two patients had normal serum levels of cTnI (< or =0.03 ng/ml) and 24 patients had elevated levels (0.015 +/- 0.007 vs. 0.053 +/- 0.029 ng/ml, p < 0.0001). No significant difference in all-cause mortality (20 vs. 4 deaths), cardiac mortality (4 vs. 1 death), all-cause hospital admissions (1.74 +/- 1.72 vs. 1.25 +/- 1.19 admissions/patient) or cardiac admissions (0.52 +/- 0.89 vs. 0.33 +/- 0.76 admissions/patient) was present between the patients with normal cTnI levels and those with elevated cTnI levels. Serum cTnI was not significantly different between patients who died versus those who survived (0.022 +/- 0.019 vs. 0.022 +/- 0.021 ng/ml). Serum cTnI was not an independent predictor of all-cause mortality, cardiac mortality, all-cause admissions or cardiac admissions. Age (older) and serum albumin (lower) were independent predictors of all-cause mortality, whereas a history of myocardial infarction was an independent predictor of cardiac mortality. Serum sodium (lower) was an independent predictor of all-cause hospital admissions, whereas hypertension and previous myocardial infarction were independent predictors of cardiac admissions. The best predictors of the time to death were age (older) and serum sodium level (lower), irrespective of the serum cTnI levels.

CONCLUSIONS

Cardiac troponin I has a limited role in predicting mortality and hospital admissions in asymptomatic patients with chronic renal failure treated with long-term hemodialysis.

Myocardial infarction with normal coronary arteries: the pathologic and clinical perspectives

Myocardial infarction with normal coronary arteries is a syndrome resulting from numerous conditions but the exact cause in a majority of the patients remains unknown. Cigarette smokers and cocaine users are more prone to develop this condition. The possible mechanisms causing myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, intense sympathetic stimulation, non-atherosclerotic coronary diseases, coronary trauma, coronary vasospasm, coronary thrombosis, and endothelial dysfunction. It primarily affects younger individuals, and the clinical presentation is similar to that of myocardial infarction with coronary atherosclerosis. Thrombolytics, aspirin, nitrates, and beta blockers should be instituted as a standard therapy for acute myocardial infarction. Once normal coronary arteries are identified on subsequent angiography, the calcium channel blockers could be added since coronary vasospasm appears to play a major role in the pathophysiology of this condition. The beta blockers should be avoided in cocaine-induced myocardial infarction because the coronary spasm may worsen. In myocardial infarction with normal coronary arteries, complications such as malignant arrhythmia, heart failure, and hypotension are generally less common, and prognosis is usually good. Recurrent infarction, postinfarction angina, heart failure, and sudden cardiac death are rare. Stress electrocardiography and imaging studies are not useful prognostic tests and long-term survival mainly depends on the residual left ventricular function, which is usually good.

Acute myocardial infarction with angiographically normal coronary arteries

The exact etiology of myocardial infarction remains unknown in a majority of the patients with normal coronary arteries. Those who smoke cigarettes and use cocaine are more prone to have this condition. The possible mechanisms underlying myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, nonatherosclerotic coronary diseases, coronary trauma, coronary vasospasm, and coronary thrombosis. Myocardial infarction with normal coronary arteries primarily affects younger persons and is distinctly rare in patients older than 50 years. We describe a case of acute myocardial infarction with normal coronary arteries in a 61-year-old woman who smoked cigarettes. The clinical perspectives and management of the myocardial infarction with normal coronary arteries are discussed.

Specificity of cardiac troponin I and creatine kinase-MB isoenzyme in asymptomatic long-term hemodialysis patients and effect of hemodialysis on these cardiac markers

OBJECTIVES

The objectives of this study were: (1) to evaluate the specificity of cardiac troponin I and creatine kinase-MB isoenzyme in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis, and (2) to evaluate the effect of hemodialysis on the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme.

METHODS

One hundred and forty-four consecutive ambulatory asymptomatic chronic renal failure patients on hemodialysis for a minimum of 1 year were evaluated clinically. Serum cardiac troponin I and creatine kinase-MB isoenzyme levels were measured with specific monoclonal antibodies before and after dialysis using ACCESS Troponin I and ACCESS CK-MB assays.

RESULTS

The specificity of serum cardiac troponin I was 83% with a cutoff level of 0.03 ng/ml, which is an expected level for healthy population, but it rose to 100% with a cutoff level of 0.15 ng/ml, which is a reference level for patients with acute myocardial infarction. Twenty-four (17%) patients had borderline elevation in cardiac troponin I (>0.03 to <0.15 ng/ml). A history of angina pectoris was more common in the borderline-elevated cardiac troponin I subgroup. In 28% of the patients, serum creatine kinase-MB isoenzyme levels were increased with a specificity of 72% at a cutoff level of 4 ng/ml, which is the upper limit of normal, but the specificity rose to 98% by increasing the cutoff level value to 10 ng/ml. There were no statistically significant differences in serum levels of cardiac troponin I and creatine kinase-MB isoenzyme before and after dialysis.

CONCLUSIONS

Cardiac troponin I is highly specific in ambulatory asymptomatic chronic renal failure patients on long-term hemodialysis; borderline elevations in cardiac troponin I may represent microinjury to the myocardium. A serum level of creatine kinase-MB isoenzyme >2.5 times of the normal upper limit may be highly specific in this patient population. Hemodialysis per se does not significantly change the serum levels of cardiac troponin I and creatine kinase-MB isoenzyme.

Elevation of serum cardiac troponin I in noncardiac and cardiac diseases other than acute coronary syndromes

This study evaluated the role of serum cardiac troponin I as a biochemical marker for the diagnosis of acute coronary syndromes in the presence of noncardiac diseases. Diagnostic characteristics were examined in 102 consecutive patients who were found to have serum cardiac troponin I levels higher than the upper reference limit of 0.6 ng/mL. Of 102 patients with cardiac troponin I levels of >0.6 ng/mL, 35 did not have the final diagnoses of acute coronary syndromes (myocardial infarction or unstable angina) but had various other final diagnoses, including nonischemic dilated cardiomyopathy, muscular disorders, central nervous system disorders, HIV disease, chronic renal failure, sepsis, lung diseases, and endocrine disorders. The mean value of serum cardiac troponin I in the patients with diseases other than acute coronary syndromes was significantly lesser than in those with acute coronary syndromes (2.0+/-1.9 [SD] v. 24.7+/-28.2 ng/mL; P<.0001). There were significantly fewer histories of chest pain and prior myocardial infarction in patients with diseases other than acute coronary syndromes than in those with acute coronary syndromes (history of chest pain, 3 v. 48 patients [P<.001]; history of prior myocardial infarction, 0 v. 30 patients [P<.001]). In conclusion, elevated serum levels of cardiac troponin I, especially in the lower ranges, should be interpreted with caution, particularly in patients suffering from acute illnesses who lack other diagnostic features suggestive of acute coronary ischemic events.

Increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease

BACKGROUND

Approximately half of patients with end-stage renal disease die because of cardiac disease, and ventricular arrhythmias are the common terminal events. Increased dispersion of the repolarization phase of the myocardial action potential can predispose patients to ventricular tachycardia and fibrillation causing cardiac death.

OBJECTIVE

To determine the existence of increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease.

STUDY DESIGN

Case-control prospective study.

PATIENTS AND METHODS

The QT dispersion and the interval between the peak of the T wave (Tp) and the end of the T wave (Te) on a surface electrocardiogram represent regional and transmyocardial dispersion in ventricular repolarization, respectively. The prehemodialysis QT dispersions and Tp-Te intervals of 94 consecutive patients with end-stage renal disease were determined and compared with those of age- and sex-matched healthy controls.

RESULTS

Both the QT and the QTc dispersion were significantly higher in the end-stage renal disease group than in the control group (QT dispersion 46 +/- 17 ms [mean +/- SD] versus 26 +/- 16 ms, P < 0.001; QTc dispersion 51 +/- 20 ms versus 30 +/- 20 ms, P < 0.001). Similarly, both the corrected average Tp-Te and the corrected maximum Tp-Te intervals were significantly higher in the end-stage renal disease group than in the control group (corrected average Tp-Te interval 99 +/- 19 ms versus 87 +/- 19 ms, P = 0.023; corrected maximum Tp-Te interval 114 +/- 23 ms versus 103 +/- 23 ms, P = 0.023).

CONCLUSIONS

Increased regional and transmyocardial dispersion of ventricular repolarization in end-stage renal disease was demonstrated. This increased dispersion may be a contributory factor in the high cardiac mortality in patients with end-stage renal disease.

Zones of atrial vulnerability. Relationships to basic cycle length

BACKGROUND

Bradycardia is commonly found in individuals at risk for paroxysmal atrial fibrillation (AF). However, a clear relationship between lengthening of basic cyclic length (BCL) and AF has not been demonstrated.

METHODS AND RESULTS

In 20 open-chest dogs, atrial refractoriness, AF vulnerability, and atrial activation times (ACTs) were determined in sinus rhythm and at BCLs of 400, 300, and 200 ms, and the findings at the same coupling intervals and stimulus strengths were compared. As BCL increased, AFV zone lengthened, and its outer limit occurred later in diastole. The outer limit of the AF vulnerability zone for a BCL was its relative refractory period; the inner limit, however, was not its effective refractory period. A border zone, defined by the inner limit of the AF vulnerability zone and the effective refractory period for a BCL, decreased as BCL lengthened, offsetting the increase in the AF vulnerability zone. The border zone was characterized by paradoxical stimulus current strength propagation relations and features suggesting supernormal conduction. ACT also increased with BCL lengthening. When AF induced by rapid atrial burst pacing was contrasted with AF induced by an extrastimulus, it tended to have a more disorganized pattern and lasted longer.

CONCLUSIONS

Lengthening of BCL increases the AF vulnerability zone, extending its outer limit later in diastole and comprising an increasing component of the total duration of the relative refractory period. Very short BCLs create conditions that also favor AF vulnerability.

An analysis of the factors which impinge on a nurse's decision to enter, stay in, leave or re-enter the nursing profession

As part of a wider study concerned with the changing nurse employment patterns a detailed questionnaire was completed by a total of 2325 qualified female nurses, 841 of whom were working fulltime in nursing, 634 were inactive, 678 were offering their services on a part-time basis and 172 were working in some other occupation. In a previous article the results of the analysis conducted on the responses to the attitude questions were presented. In this paper the replies to those questions aimed at soliciting the reasons felt to have impacted on the respondent's decision to take up nursing, to stay or to leave the profession and to re-enter the profession are analysed. As the questionnaires were distributed in the course of two projects separated by 4 years, what is of particular interest is the similarity of the two sets of results. These indicate that there is still a very high level of job satisfaction as evidenced by the extent to which nursing would be recommended to a friend or relative. The primary obvious reason for inactivity is the existence of a young child but when further intentions are explored it is clear that there is a large pool of qualified nurses keen to resume a career the main obstacle being the lack of sufficient flexibility of hours of working.

Attitudes of 2325 active and inactive nurses to aspects of their work

As a part of an ongoing larger study concerned with nurse manpower planning, an attempt has been made to investigate the reasons for the non-participation in the labour force of such a large proportion of qualified nurses. In an attempt to collect information on this topic a questionnaire was developed and distributed to a sample of nurses. The article describes in some detail the two different ways in which the names and addresses of the sample were generated. The first method involved making contact by the simple expedient of dropping leaflets through letterboxes while the second involved tracing respondents through their last known address when they originally qualified. The success of these two approaches is contrasted which should be of value to anyone contemplating a similar name-capturing exercise. A total of 2325 questionnaires were returned and computer analysed. This article presents the results of one part of that analysis i.e. the factor analysis conducted on the attitudinal questions contained in the document. A five-factor solution yielded highly interpretable results and the factor loadings are presented along with the pattern of responses. The factor scores are then contrasted for three different groups of respondents: the grouping being based on whether the respondent was working full-time, part-time or not at all.