Trends in elder abuse and age discrimination during the COVID-19 pandemic in Hong Kong: Findings from a two-wave representative telephone survey study.

OBJECTIVES: Empirical evidence about the heightened risks of elder abuse and age discrimination during the COVID-19 pandemic is scarce. This study aimed to track the changes in rates of both, and investigated their associated factors in the community-dwelling older population in Hong Kong. METHODS: In this two-wave, cross-sectional telephone survey, we interviewed a population-based sample of individuals (≥55 years), and captured the situation of elder abuse and age discrimination before the COVID-19 outbreak (n = 1209, Wave 1: October-December 2019) and during the pandemic (n = 891, Wave 2: December 2020-January 2021). Participants reported their experiences of different types of abuse and discrimination, financial health, subjective well-being, satisfaction with environment, health and social services, and resilience. RESULTS: Abuse was reported by 20.2% of the sample before the outbreak and 17.8% during the pandemic; while discrimination was reported by 24.6% and 29.8% at the two time points, respectively. A drop in physical abuse was observed, but it was accompanied by a rise in discrimination in the form of harassment or refusal of services. Findings of logistic regression analysis show that abuse during the pandemic was associated with younger age, poorer subjective well-being, and lower resilience; while discrimination was associated with female gender, being married, and poorer subjective well-being. CONCLUSIONS: Elder abuse and discrimination were prevalent across time points. The pandemic has highlighted the marginalization of older persons in our communities. There is an urgent need for development of effective interventions to end abuse and discrimination.

Typology of family caregivers of older persons: A latent profile analysis using elder mistreatment risk and protective factors.

This study sought to identify subpopulations of caregivers of older persons based on their profiles of individual characteristics and caregiving contexts and aimed at examining the associations between caregiver profiles and elder mistreatment. A convenient sample of 600 adult caregivers of community-dwelling older people in Hong Kong participated. Results of latent profile analysis support a typology of 3 distinctive caregiver profiles: (a) non-vulnerable caregivers; (b) isolated, vulnerable caregivers; and (c) traumatized, vulnerable caregivers. Isolated and traumatized caregivers reported greater risk factors related to elder mistreatment: They had higher levels of caregiver stress and burden, lower levels of social support and resilience, greater neurotic personality orientation and problematic gambling behavior, and more severe childhood traumatic experiences. The two groups also display significantly higher level of abusive behaviors than non-vulnerable caregivers.

Staff Turnover Intention at Long-Term Care Facilities: Implications of Resident Aggression, Burnout, and Fatigue.

OBJECTIVES: Staff shortages and the high turnover rate of nursing assistants pose great challenges to long-term care. This study examined the effects of aggression from residents of long-term care facilities, burnout, and fatigue on staff turnover intention. The findings will help managers to devise effective measures to retain their staff. DESIGN: Cross-sectional descriptive study design. SETTING AND PARTICIPANTS: A total of 800 nursing assistants were recruited from 70 long-term care facilities using convenience sampling. METHODS: The participants were individually interviewed and provided information about their turnover intention, resident aggression witnessed and experienced, self-efficacy, neuroticism, burnout, fatigue, and personal and facility characteristics. RESULTS: Hierarchical multiple regression analysis revealed that the size and organizational practices of long-term care facilities were not associated with staff turnover intention. Staff who spent less time in the industry reported witnessing resident-to-resident aggression, experienced resident-to-staff aggression, reported high levels of burnout, had acute or chronic fatigue, and had low levels of inter-shift recovery were more likely than others to report a high turnover intention. CONCLUSIONS AND IMPLICATIONS: Staff turnover poses great challenges to staff, residents, and organizations. This study identified important factors that may help support staff in long-term care facilities. Specific measures, such as person-centered care to diminish resident aggression by addressing residents' unmet needs, work-directed programs to mitigate burnout and improve staff mental health, and flexible schedules to prevent fatigue should also be advocated to prevent staff turnover.

Physical, psychological and pandemic fatigue in the fourth wave of COVID-19 outbreak in Hong Kong: population-based, cross-sectional study.

OBJECTIVES: To examine the physical, psychological and pandemic fatigue during the COVID-19 pandemic, and to explore the correlates of fatigue using a representative, population-based, community sample of Chinese adults in Hong Kong. DESIGN: Cross-sectional study. SETTING: Telephone surveys in Hong Kong from December 2020 to January 2021 (during the fourth wave of COVID-19 outbreak). PARTICIPANTS: 1255 adults living in Hong Kong aged 18 years or older sampled using a multistage approach (53% women). MAIN OUTCOME MEASURES: Physical and psychological fatigue: The Fatigue Assessment Scale (with a cut-off score of 22). Pandemic fatigue: Adherence to six disease prevention measures (DPM) recommended by the government. RESULTS: About 25.7% of the participants were feeling fatigued physically and psychologically. Physical and psychological fatigue was not directly associated with pandemic fatigue, and their association was fully mediated by self-perceived disruptions of COVID-19-related restrictions in daily life. Results from the hierarchical regression analysis showed that higher levels of fatigue were associated with economically inactive status (B=0.18, SE=0.04, p<0.001), having family or friend infected with COVID-19 before or during the study (B=0.17, SE=0.01, p<0.001), lower acceptability of DPM (B=-0.16, SE=0.03, p<0.001), greater disruptions in daily life (B=0.22, SE=0.02, p<0.001), and greater trust in authorities in ending the pandemic (B=0.11, SE=0.02, p<0.001). CONCLUSIONS: Fatigue affected many individuals during the pandemic. Disruptions of DPM in daily life may serve as a mediator in the association between pandemic fatigue and physical and psychological fatigue, reflecting the need of effective interventions to reduce self-perceived disruptions of COVID-19-related restrictions in the general population. Resources should be allocated to provide sufficient services to individuals vulnerable to fatigue during the prolonged pandemic.

Predictors of COVID-19 actual vaccine uptake in Hong Kong: A longitudinal population-based survey.

Purpose of the research: Identifying predictors of COVID-19 vaccine uptake decisions is central to the development of evidence-based strategies for promoting vaccination. This longitudinal study investigated the link between previous willingness to vaccinate and vaccine uptake decision, and examined potential predictors of vaccine uptake in Hong Kong. Methods: A longitudinal telephone survey study was conducted using a population-based sample of Chinese adult residents (≥18 years) in Hong Kong. Data were collected at two time points: T1 (December 2020-January 2021) and T2 (June-July 2021). Primary outcome was vaccine uptake status; whilst independent variables and covariates included socio-demographic factors, COVID-19 related experiences, health beliefs, and perception, as well as vaccine related perceptions. Results: Among the 1,003 participants, 23.7% had received a COVID-19 vaccine. Previous willingness to vaccinate did not predict vaccine uptake at later stage. Vaccine uptake by known others (aOR = 8.00), trust in authorities (aOR = 1.53), acceptability of non-pharmaceutical preventive measures (aOR = 2.96), and first-hand experience of COVID-19 (aOR = 1.32) were significant predictors of vaccine uptake after adjusting for confounding factors. Conclusions: Future strategies to promote vaccination may focus on building public trust in government and healthcare professional, and encouraging vaccinated individuals to share their vaccine uptake status via social networking.

Fas ligand in human serum.

The Fas ligand (FasL), a member of the tumor necrosis factor family, induces apoptosis in Fas-bearing cells. The membrane-bound human FasL was found to be converted to a soluble form (sFasL) by the action of a matrix metalloproteinase-like enzyme. Two neutralizing monoclonal anti-human FasL antibodies were identified, and an enzyme-linked immunosorbent assay (ELISA) for sFasL in human sera was established. Sera from healthy persons did not contain a detectable level of sFasL, whereas those from patients with large granular lymphocytic (LGL) leukemia and natural killer (NK) cell lymphoma did. These malignant cells constitutively expressed FasL, whereas peripheral NK cells from healthy persons expressed FasL only on activation. These results suggested that the systemic tissue damage seen in most patients with LGL leukemia and NK-type lymphoma is due to sFasL produced by these malignant cells. Neutralizing anti-FasL antibodies or matrix metalloproteinase inhibitors may be of use in modulating such tissue damage.

Predicting Public Adherence to COVID-19 Preventive Measures: A Cross-Sectional Study in Hong Kong.

Objectives: To effectively control the spread of COVID-19, the public's adherence to relevant disease preventive measures (DPM) is critical. This study examined individuals' adherence to various DPM and identified facilitators and barriers to adherence in a community sample in Hong Kong. Methods: In this cross-sectional study, telephone surveys were conducted over December 2020 and January 2021. Participants provided responses on their adherence to DPM as well as other psychosocial and cognitive factors via the phone. Results: Of the sample of 1255 Chinese adults (aged >18 years, 53% women), 94.4% wore face masks in public areas; 88.4% avoided touching their eyes, nose, and mouth; 82.1% performed hand hygiene practices; 81.5% used alcohol-based hand rubs; 74.6% abided by social distancing; and 39.7% tested for COVID-19 on a voluntary basis. Perceived benefits, perceived barriers, self-efficacy, cues to action, perceived acceptability, and disruptions to daily life related to COVID-19 were associated with individuals' adherence to DPM. Conclusions: Adherence to DPM was strong in Hong Kong, and the adherence level could be predicted by various factors. It is vital to consider these factors in order to improve the public's adherence.

Endoplasmic reticulum stress-induced formation of transcription factor complex ERSF including NF-Y (CBF) and activating transcription factors 6alpha and 6beta that activates the mammalian unfolded protein response.

The levels of molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) are controlled by a transcriptional induction process termed the unfolded protein response (UPR). The mammalian UPR is mediated by the cis-acting ER stress response element (ERSE), the consensus sequence of which is CCAAT-N(9)-CCACG. We recently proposed that ER stress response factor (ERSF) binding to ERSE is a heterologous protein complex consisting of the constitutive component NF-Y (CBF) binding to CCAAT and an inducible component binding to CCACG and identified the basic leucine zipper-type transcription factors ATF6alpha and ATF6beta as inducible components of ERSF. ATF6alpha and ATF6beta produced by ER stress-induced proteolysis bind to CCACG only when CCAAT is bound to NF-Y, a heterotrimer consisting of NF-YA, NF-YB, and NF-YC. Interestingly, the NF-Y and ATF6 binding sites must be separated by a spacer of 9 bp. We describe here the basis for this strict requirement by demonstrating that both ATF6alpha and ATF6beta physically interact with NF-Y trimer via direct binding to the NF-YC subunit. ATF6alpha and ATF6beta bind to the ERSE as a homo- or heterodimer. Furthermore, we showed that ERSF including NF-Y and ATF6alpha and/or beta and capable of binding to ERSE is indeed formed when the cellular UPR is activated. We concluded that ATF6 homo- or heterodimers recognize and bind directly to both the DNA and adjacent protein NF-Y and that this complex formation process is essential for transcriptional induction of ER chaperones.

ATF6 activated by proteolysis binds in the presence of NF-Y (CBF) directly to the cis-acting element responsible for the mammalian unfolded protein response.

Transcription of genes encoding molecular chaperones and folding enzymes in the endoplasmic reticulum (ER) is induced by accumulation of unfolded proteins in the ER. This intracellular signaling, known as the unfolded protein response (UPR), is mediated by the cis-acting ER stress response element (ERSE) in mammals. In addition to ER chaperones, the mammalian transcription factor CHOP (also called GADD153) is induced by ER stress. We report here that the transcription factor XBP-1 (also called TREB5) is also induced by ER stress and that induction of CHOP and XBP-1 is mediated by ERSE. The ERSE consensus sequence is CCAAT-N(9)-CCACG. As the general transcription factor NF-Y (also known as CBF) binds to CCAAT, CCACG is considered to provide specificity in the mammalian UPR. We recently found that the basic leucine zipper protein ATF6 isolated as a CCACG-binding protein is synthesized as a transmembrane protein in the ER, and ER stress-induced proteolysis produces a soluble form of ATF6 that translocates into the nucleus. We report here that overexpression of soluble ATF6 activates transcription of the CHOP and XBP-1 genes as well as of ER chaperone genes constitutively, whereas overexpression of a dominant negative mutant of ATF6 blocks the induction by ER stress. Furthermore, we demonstrated that soluble ATF6 binds directly to CCACG only when CCAAT exactly 9 bp upstream of CCACG is bound to NF-Y. Based on these and other findings, we concluded that specific and direct interactions between ATF6 and ERSE are critical for transcriptional induction not only of ER chaperones but also of CHOP and XBP-1.

Mammalian transcription factor ATF6 is synthesized as a transmembrane protein and activated by proteolysis in response to endoplasmic reticulum stress.

The unfolded protein response (UPR) controls the levels of molecular chaperones and enzymes involved in protein folding in the endoplasmic reticulum (ER). We recently isolated ATF6 as a candidate for mammalian UPR-specific transcription factor. We report here that ATF6 constitutively expressed as a 90-kDa protein (p90ATF6) is directly converted to a 50-kDa protein (p50ATF6) in ER-stressed cells. Furthermore, we showed that the most important consequence of this conversion was altered subcellular localization; p90ATF6 is embedded in the ER, whereas p50ATF6 is a nuclear protein. p90ATF6 is a type II transmembrane glycoprotein with a hydrophobic stretch in the middle of the molecule. Thus, the N-terminal half containing a basic leucine zipper motif is oriented facing the cytoplasm. Full-length ATF6 as well as its C-terminal deletion mutant carrying the transmembrane domain is localized in the ER when transfected. In contrast, mutant ATF6 representing the cytoplasmic region translocates into the nucleus and activates transcription of the endogenous GRP78/BiP gene. We propose that ER stress-induced proteolysis of membrane-bound p90ATF6 releases soluble p50ATF6, leading to induced transcription in the nucleus. Unlike yeast UPR, mammalian UPR appears to use a system similar to that reported for cholesterol homeostasis.

Elevated levels of oxidized low density lipoprotein show a positive relationship with the severity of acute coronary syndromes.

BACKGROUND: There is accumulating data that acute coronary syndromes relate to recent onset activation of inflammation affecting atherosclerotic plaques. Increased blood levels of oxidized low density lipoprotein (ox-LDL) could play a role in these circumstances. METHODS AND RESULTS: Ox-LDL levels were measured in 135 patients with acute myocardial infarction (AMI; n=45), unstable angina pectoris (UAP; n=45), and stable angina pectoris (SAP; n=45) and in 46 control subjects using a sandwich ELISA method. In addition, 33 atherectomy specimens obtained from a different cohort of patients with SAP (n=10) and UAP (n=23) were studied immunohistochemically for ox-LDL. In AMI patients, ox-LDL levels were significantly higher than in patients with UAP (P<0.0005) or SAP (P<0.0001) or in controls (P<0.0001) (AMI, 1.95+/-1.42 ng/5 microgram LDL protein; UAP, 1.19+/-0.74 ng/5 microgram LDL protein; SAP, 0.89+/-0.48 ng/5 microgram LDL protein; control, 0.58+/-0.23 ng/5 microgram LDL protein). Serum levels of total, HDL, and LDL cholesterol did not differ among these patient groups. In the atherectomy specimens, the surface area containing ox-LDL-positive macrophages was significantly higher in patients with UAP than in those with SAP (P<0.0001). CONCLUSIONS: This study demonstrates that ox-LDL levels show a significant positive correlation with the severity of acute coronary syndromes and that the more severe lesions also contain a significantly higher percentage of ox-LDL-positive macrophages. These observations suggest that increased levels of ox-LDL relate to plaque instability in human coronary atherosclerotic lesions.

Transient left ventricular apical ballooning without coronary artery stenosis: a novel heart syndrome mimicking acute myocardial infarction. Angina Pectoris-Myocardial Infarction Investigations in Japan.

OBJECTIVES: To determine the clinical features of a novel heart syndrome with transient left ventricular (LV) apical ballooning, but without coronary artery stenosis, that mimics acute myocardial infarction, we performed a multicenter retrospective enrollment study. BACKGROUND: Only several case presentations have been reported with regard to this syndrome. METHODS: We analyzed 88 patients (12 men and 76 women), aged 67 +/- 13 years, who fulfilled the following criteria: 1) transient LV apical ballooning, 2) no significant angiographic stenosis, and 3) no known cardiomyopathies. RESULTS: Thirt-eight (43%) patients had preceding aggravation of underlying disorders (cerebrovascular accident [n = 3], epilepsy [n = 3], exacerbated bronchial asthma [n = 3], acute abdomen [n = 7]) and noncardiac surgery or medical procedure (n = 11) at the onset. Twenty-four (27%) patients had emotional and physical problems (sudden accident [n = 2], death/funeral of a family member [n = 7], inexperience with exercise [n = 6], quarreling or excessive alcohol consumption [n = 5] and vigorous excitation [n = 4]). Chest symptoms (67%), electrocardiographic changes (ST elevation [90%], Q-wave formation [27%] and T-wave inversion [97%]) and elevated creatine kinase (56%) were found. After treatment of pulmonary edema (22%), cardiogenic shock (15%) and ventricular tachycardia/fibrillation (9%), 85 patients had class I New York Heart Association function on discharge. The LV ejection fraction improved from 41 +/- 11% to 64 +/- 10%. Transient intraventricular pressure gradient and provocative vasospasm were documented in 13/72 (18%) and 10/48 (21%) of the patients, respectively. During follow-up for 13 +/- 14 months, two patients showed recurrence, and one died suddenly. CONCLUSIONS: A novel cardiomyopathy with transient apical ballooning was reported. Emotional or physical stress might play a key role in this cardiomyopathy, but the precise etiologic basis still remains unclear.

Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction.

To investigate the clinical application of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) in the management of acute myocardial infarction (AMI), we examined 44 patients with AMI within 1 month after onset. Enhanced images were classified into 4 types: nontransmural (type 1), transmural and homogeneous (type 2), transmural and marginal (type 3), and no enhancement (type 4). Each enhancement pattern was correlated with angiographic and thallium-201 imaging results. The redistribution images of thallium were graded on a 4-point scale from 0 (normal) to 3 (markedly reduced or absent activity). The percentage of the perimeter affected by asynergy was obtained from the left ventriculogram. Peak creatine kinase and the percentage of asynergic perimeter were significantly higher in type 3 than in other type patients. End-diastolic volume index was significantly higher in type 3 than in type 2 patients. Left ventricular ejection fraction was lowest, and end-systolic volume index, thallium-201 score, and incidence of wall thinning on MRI were highest in type 3 patients. Therefore, the transmural and marginal enhancement pattern (type 3) was compatible with extensive myocardial infarction with infarct expansion and less viable myocardium. In the other types, the infarction was small to moderate in size and left ventricular function was well preserved. Thus, Gd-DTPA-enhanced MRI may be useful in the evaluation of left ventricular function and myocardial viability of the infarct region after AMI.

Effects of aspirin DL-lysine on thrombin generation in unstable angina pectoris.

To evaluate the effects of aspirin on thrombin generation in patients with unstable angina, plasma levels of thrombin-antithrombin III complex (TAT) as a new marker of thrombin generation and of 11-dehydro-thromboxane B2 (11-dehydro-TXB2) as an indicator of platelet activation were measured in 18 patients with unstable angina, including 8 patients with prolonged rest angina (> 15 minutes). Aspirin DL-lysine (900 mg) was administered intravenously to 9 of the 18 patients (aspirin group); the other 9 were not given aspirin during the first 24 hours of hospitalization (non-aspirin group). Clinical characteristics, angiographic features and medications other than aspirin were similar between the 2 groups. Levels of plasma TAT and 11-dehydro-TXB2 were significantly higher (p < 0.05) in patients with prolonged rest angina than in those without the condition (n = 10). In 5 patients with prolonged rest angina who received aspirin, plasma TAT levels (ng/ml) were significantly decreased (4.52 +/- 1.18 at baseline, 2.50 +/- 0.65 at 1 hour and 2.16 +/- 0.42 at 24 hours after aspirin administration, p < 0.01) with a significant decrease in plasma 11-dehydro-TXB2 levels. However, the reduction in TAT after aspirin administration was slight in patients without prolonged rest angina (n = 4). In contrast, levels of plasma TAT and 11-dehydro-TXB2 in the non-aspirin group remained unchanged during the study period. These results suggest that aspirin rapidly reduces thrombin generation through inhibition of platelet activity in patients with unstable angina with prolonged rest angina.

Multiple coronary artery dissections diagnosed in vivo in a pregnant woman.

A 27-year-old, 37-weeks' primigravida survived an acute myocardial infarction. Coronary angiography 25 days after infarction demonstrated multiple dissections in the left coronary artery. She had no vascular risk factors or connective tissue disease. This is a rare case of spontaneous, multiple coronary artery dissections that were diagnosed by coronary angiography.

Age-related changes of clinical features and prevalences of coronary risk factors in Japanese patients with vasospastic angina.

From among 899 consecutive patients who underwent their first coronary arteriography, we selected 147 pts with vasospastic angina (VA) and 356 pts with classic angina (CA) and divided them into three different age groups: -49 years old, 50 to 59, and 60-. In these 899 pts, incidences of VA showed no increase with aging. Prevalence of coronary risk factors in CA, such as diabetes, hypercholesterolemia, hypertension, and obesity, was higher than in VA, although prevalence of smoking in CA was lower than in VA. In VA, we found an age-related increase in the incidence of smoking only, in contrast to the other four risk factors. The VA showed no age-related increase in the incidence of complication of fixed coronary stenosis. These findings suggest that aging and atherosclerosis might not play a major role in pathogenesis of VA, although the mere presence of atherosclerosis irrespective of its severity could interact with local susceptibility to spasm, leading to coronary vasospasm.

Abnormal heart rate control in vasospastic angina: effects of calcium antagonists.

We examined the effects of administration of calcium antagonists on the heart rate response to treadmill exercise in 11 patients with vasospastic angina and 8 healthy young volunteers. The exercise test was performed by walking on a treadmill at a constant speed and grade according to a scheme of pseudo-randomized sequence for 19 min. The dynamic property of heart rate response to exercise was evaluated by using a frequency analytic procedure. The exercise test was also studied in 21 age-matched normal controls without drug administration. Administration of calcium antagonists revealed no significant effects on heart rate and blood pressure at rest in young healthy subjects or in patients with vasospastic angina. Young volunteers showed the same normal properties of heart rate response to exercise before and after calcium antagonists. Vasospastic angina showed abnormal heart rate response to exercise and revealed characteristically different transfer function from that in normal controls. These characteristics were not affected by treatment with calcium antagonists except for a slight, uniform decrease of gain of the system over the whole frequency range. Accordingly, the present exercise test can feasibly be used in the diagnosis and management of vasospastic angina even when calcium antagonists are administered to the patients.

Lipoprotein analyses in patients with stable angina and acute coronary syndrome.

We have performed lipid analyses by using a table-top ultracentrifuge based on the Hatch and Lees' method in 77 subjects (60 men, 17 women: mean age, 63 years) to clarify lipoprotein disorders in coronary artery disease. Sixty-four subjects had coronary artery disease and 13 normal subjects were controls. They were divided into the groups with stable angina pectoris and with unstable angina pectoris or acute myocardial infarction (acute coronary syndromes). In patients with coronary artery disease, there were no significant differences from control in age, body mass index, total cholesterol, however, HDL cholesterol was significantly lower than those in the controls. LDL cholesterol:LDL apoB ratio, which is thought to reflect the size of LDL in coronary artery disease, was significantly smaller than that in the controls; mean values were 1.2 in coronary artery disease and 1.4 in controls. There were no significant differences in those lipoprotein disorders between the patients with stable angina and those with acute coronary syndromes. Though these lipoprotein abnormalities would not play a trigger role in acute coronary syndrome, they are characteristic of the lipid profile of patients with coronary artery disease.

Delayed recovery of myocardial perfusion after successful coronary angioplasty of infarct-related artery in patients with prior myocardial infarction.

We studied the status of myocardial perfusion before and after coronary angioplasty (PTCA) of infarct-related artery using stress thallium scan in patients with prior myocardial infarction. Twenty-six patients who had anterior myocardial infarction caused by single-vessel disease at the left anterior descending coronary artery were involved. Patients were classified into the following four groups according to the stress-redistribution thallium scintigraphic findings before PTCA: complete redistribution (two cases), incomplete redistribution (12 cases), partial redistribution (seven cases) and no redistribution (five cases). In the group with complete redistribution, the extent of residual ischaemia in the infarct area decreased significantly after PTCA but infarct size only slightly. In the groups with incomplete and partial redistribution, the extent of residual ischaemia and infarct size decreased significantly after PTCA. In contrast, the group with no redistribution showed a slight decrease in the extent of residual ischaemia and a gradual decrease in infarct size beginning 3 months after PTCA. Clinical findings including electrocardiogram indicated that the patients with incomplete redistribution had more viable myocardium and the patients with no redistribution had more scarring. The groups with incomplete and partial redistribution showed characteristics intermediate between complete and no redistribution. The change of infarct area after PTCA was different between the four groups, but both residual ischaemia and infarct size decreased in all groups. Thus, PTCA of the infarct-related coronary artery is useful even in the patients with prior myocardial infarction, even in patients with no redistribution shown by stress thallium scan.

Poor responsiveness of heart rate to treadmill exercise in vasospastic angina.

Heart rate response to submaximal graded treadmill exercise was measured in 45 patients with vasospastic angina, 31 with effort angina, and 40 normal controls. There was no difference of resting heart rate among the three groups. Vasospastic angina showed significantly poor responsiveness of heart rate to exercise at every stage: stage 1, 2.5 km/h (10%), stage 3, 4.5 km/h (10%), stage 5, 5.5 km/h (14%), stage 7, 5.5 km/h (22%), when compared with those in normal controls. The effort angina group also showed lower heart rates at stages 3 and 5 than those in control subjects, although their heart rate at stage 1 was not different from that in normals. When abnormal response suggesting vasospastic angina was defined as heart rate at each stage lower than values of mean heart rate +/- 1 SD in normal controls, positive test results were obtained in 15 of 45 patients (33%). The use of heart rate criteria in addition to ischemic criteria raises sensitivity from 27 to 51% (p less than 0.02).