5968Adherence to driving restrictions among patients with an implantable cardioverter defibrillator: insights from a nationwide register-linked survey study

Background

Patients with an implantable cardioverter defibrillator (ICD) are restricted from driving following initial implantation or ICD shock. It is unclear how many patients are aware of, and adhere to, these restrictions.

Purpose

To investigate knowledge of, and adherence to, private and professional driving restrictions in a nationwide cohort of ICD patients.

Methods

A questionnaire was distributed to all living Danish residents ≥18 years who received a first-time ICD between 2013 and 2016 (n=3,913). During this period, Danish guidelines recommended 1 week driving restriction following ICD implantation for primary prevention, and 3 months following either ICD implantation for secondary prevention or appropriate ICD shock, and permanent restriction of professional driving and driving of large vehicles (>3.5 metric tons). Questionnaires were linked with relevant nationwide registries. Logistic regression was applied to identify factors associated with non-adherence.

Results

Of 2,741 questionnaire respondents, 92% (n=2,513) held a valid private driver's license at time of ICD implantation (85% male; 46% primary prevention indication; median age: 67 years (IQR: 59–73)). Of these, 7% (n=175) were actively using a professional driver's license for truck driving (n=73), bus driving (n=45), taxi driving (n=22), large vehicle driving for private use (n=54), or other purposes (n=32) (multiple purposes allowed).

Only 42% of primary prevention patients, 63% of secondary prevention patients, and 72% of patients who experienced an appropriate ICD shock, recalled being informed of any driving restrictions. Only 45% of professional drivers recalled being informed about specific professional driving restrictions (Figure). Most patients (93%, n=2,344) resumed private driving after ICD implantation, more than 30% during the driving restriction period: 34% of primary prevention patients resumed driving within 1 week, 43% of secondary prevention patients resumed driving within 3 months, and 30% of patients who experienced an appropriate ICD shock resumed driving within 3 months. Professional driving was resumed by 35%. Patients who resumed driving within the restricted periods were less likely to report having received information about driving restrictions (all p<0.001) (Figure).

In a multiple logistic regression model, non-adherence was predicted by reporting non-receipt of information about driving restrictions (OR: 3.34, CI: 2.27–4.03), as well as male sex (OR: 1.53, CI: 1.17–2.01), age ≥60 years (OR: 1.20, CI: 1.02–1.64), receipt of a secondary prevention ICD (OR: 2.2, CI: 1.80–2.62), and being the only driver in the household (OR: 1.29, CI: 1.05–1.57).

Conclusion

In this nationwide survey study, many ICD patients were unaware of the driving restrictions, and many ICD patients, including professional drivers, resumed driving within the restricted periods. More focus on communicating driving restrictions might improve adherence.

Acknowledgement/Funding

Danish Heart Foundation, Arvid Nilsson Foundation, Fraenkels Mindefond

The impact of heart failure on prognosis of diabetic and non-diabetic patients with myocardial infarction: a 15-year follow-up study

BACKGROUND

Information about the occurrence of heart failure in the acute phase of myocardial infarction (MI) in diabetic patients and its impact on prognosis are sparse.

AIM

The purpose of the present study was to describe how MI patients with diabetes mellitus (DM) differed from MI patients without DM with respect to the occurrence of heart failure and with respect to the influence of heart failure on mortality during follow-up 30 days extending to 15 years.

METHODS

The study is a retrospective long-term follow-up of prospectively recorded data concerning 1954 consecutive cases of MI admitted to one coronary care unit (CCU) between 1979 and 1983. DM was diagnosed in 10% (n=194), with 17% (n=33) on insulin therapy. Patients with DM comprised of a higher proportion of women (DM 36% vs. no DM 26%, P<0.001) compared with non-diabetic patients. Baseline risk factors were more prevalent in the patients with DM. The cumulative incidence of heart failure was higher among patients with than without DM (DM 54% vs. no DM 34%, P<0.001). The incidence of life-threatening arrhythmias were similar in both groups. Only 2% of patients with DM and heart failure survived 10 years of follow-up compared with 15% of the non-diabetic patients with heart failure (P<0.001). In multivariate analysis DM was not independently associated with 30 days mortality. During long-term follow-up DM was an important risk factor for mortality independent on the presence of heart failure.

CONCLUSION

DM disposes to the development of heart failure. In acute myocardial infarction diabetic patients with heart failure have a worse prognosis than non-diabetic patients with heart failure.

Long-term prognosis of diabetic patients with myocardial infarction: relation to antidiabetic treatment regimen. The TRACE Study Group

AIMS

The present study was performed to evaluate pre-admission history, presentation, initial treatment and long-term mortality in patients with myocardial infarction and diabetes.

METHODS AND RESULTS

Between 1990 and 1992, 6676 patients with acute myocardial infarction were screened for entry into the Trandolapril Cardiac Evaluation (TRACE) study. In this cohort 719 (11%) of the patients had a history of diabetes. Among the diabetic patients 19% were treated with insulin, 52% with oral hypoglycaemic agents and 29% with diet only. The diabetic patients were slightly older, more likely to be female and had a higher prevalence of known cardiovascular disease. Even though the diabetic patients had the same frequency of ST-segment elevation on the electrocardiogram and the same admission delay, treatment with thrombolysis and aspirin was less frequently prescribed to the diabetic patients than to patients without diabetes. The mortality rate was significantly increased in the diabetic patients, 7-year mortality being 79% in insulin-treated, 73% in tablet-treated and 62% in diet-treated diabetic patients compared with 46% in patients without diabetes. In a multivariate analysis only diabetic patients treated with oral hypoglycaemic agents or with insulin had an increased mortality compared with non-diabetic patients.

CONCLUSIONS

Patients with diabetes mellitus and myocardial infarction are treated with thrombolysis to a lesser extent than non-diabetic patients. Diabetic patients treated with oral hypoglycaemic agents or insulin, but not those treated with diet alone, have a significantly increased mortality following acute myocardial infarction compared with non-diabetic patients.

Accelerating impact of diabetes mellitus on mortality in the years following an acute myocardial infarction. TRACE Study Group. Trandolapril Cardiac Evaluation

AIMS

The development of risk associated with diabetes mellitus during long-term follow-up after a myocardial infarction has not been studied in detail. We have studied time-related changes of risk of death during 10 years of follow-up in a cohort of patients not treated with thrombolytic therapy (the Glostrup cohort) and during 6 years in a cohort receiving such treatment in 40% of cases (the TRACE cohort).

METHODS

A subgroup analysis of two cohorts: the Glostrup cohort, which consisted of consecutive cases of acute myocardial infarction who were admitted to one hospital between 1979 and 1983; the TRACE cohort which was comprised of patients with an acute myocardial infarction screened for entry into the Trandolapril Cardiac Evaluation study between May 1990 and June 1992. The Glostrup cohort consisted of 1954 patients and follow-up was for 10 years, The TRACE cohort consisted of 6676 patients and follow-up was for 6 years. Outcome measure was total death.

RESULTS

A diagnosis of diabetes mellitus was present in 12% of the two study populations. In multivariate analysis, diabetes mellitus had an independent adverse effect on mortality which increased with time. In the Glostrup cohort risk ratio between day 0 and day 30 was 1.17 and increased to 2.51 (P=0.0002) 7-9 years after discharge from hospital. A similar increase in the risk ratio of diabetes mellitus on mortality was observed in the TRACE cohort (risk ratio for days 0-30 was 1.03, and for years 4-6 was 1.74 (P=0.0001).

CONCLUSION

Diabetes mellitus has no independent influence on mortality immediately following an acute myocardial infarction, but has an important influence on long-term mortality which increases with time. The implication is that the effect of intervention against diabetes in patients with acute myocardial infarction and diabetes mellitus must be evaluated over a long course of time.

Effects of amlodipine and isosorbide dinitrate on exercise-induced and ambulatory ischemia in patients with chronic stable angina pectoris

This study was designed to compare once-daily administration of 5-10 mg amlodipine with two daily doses of 40 mg sustained-release isosorbide dinitrate in 59 patients with stable angina using a randomized, double-blind, crossover study design. Anginal episodes, nitroglycerin consumption, and possible adverse events were recorded in a diary. A maximal symptom-limited bicycle exercise test and 48-hour ambulatory ECG monitoring were performed at baseline and at the end of each 5-week period of therapy. Exercise time, time to angina, time to ST depression, and maximal ST depression were measured during exercise. During ambulatory monitoring, the number of ischemic episodes and the duration per hour of ST depression were assessed. Amlodipine significantly reduced anginal episodes (P < 0.001) when compared with isosorbide dinitrate. Furthermore, amlodipine prolonged time to ST depression (P < 0.001) and time to angina (P < 0.05) when compared with isosorbide dinitrate. The number and duration of ischemic episodes during ambulatory monitoring were significantly reduced with amlodipine when compared with baseline values (P < 0.05), whereas no differences were found between isosorbide dinitrate and baseline. Adverse events were reported more frequently with isosorbide dinitrate than with amlodipine (P < 0.02). Amlodipine appears to be more effective and tolerable than sustained-release isosorbide dinitrate as monotherapy for chronic stable angina.

Do diabetes mellitus and systemic hypertension predispose to left ventricular free wall rupture in acute myocardial infarction?

Diabetes and systemic hypertension had no influence on left ventricular free wall rupture complicating acute myocardial infarction. Age <65 years and a history of coronary artery disease offers some protection from protection.

Age-related mortality, clinical heart failure, and ventricular fibrillation in 4259 Danish patients after acute myocardial infarction

AIMS

To evaluate the prognosis of patients > or = 80 years old, we analysed a large, community-based population with acute myocardial infarction who received intensive observation and similar pharmacotherapy regardless of age.

METHODS AND RESULTS

In a 12-year period, before the introduction of thrombolysis, 4259 consecutive patients hospitalized with acute myocardial infarction from the same hospital in Denmark were prospectively registered. Their complications and mortality in hospital, and 1 and 5 years after discharge were analysed retrospectively. Overall, in-hospital mortality was 11% for patients less than < 50 years old, 22% for patients 60-69 years old and 43% for patients > or = 80 years old. Two thirds of patients > or = 80 years old had heart failure, and cardiogenic shock was twice as common in this age group than in patients 60-69 years. Heart failure was a strong independent risk, factor for post-discharge mortality, particularly in the oldest age groups. Four out of eight patients > or = 80 years survived one year if discharged alive after experiencing in-hospital ventricular fibrillation.

CONCLUSION

The life-saving potential of preventing or treating heart failure seems considerable even in the oldest patient groups. Patients > or = 80 years old who survive in-hospital ventricular fibrillation have an acceptable prognosis 1 year post-discharge.

Does in-hospital ventricular fibrillation affect prognosis after myocardial infarction?

AIM

The aim of this study was to estimate the prognostic information to be gained from ventricular fibrillation in patients with myocardial infarction.

METHODS AND RESULTS

We studied 4259 consecutive patients with myocardial infarction admitted to one centre in 1977-1988. Five hundred and twenty-eight (12.4%) of the patients had ventricular fibrillation in hospital. The following risk factors were included in multivariate models to estimate their importance for 30-day and long-term (median 7 year) prognosis: age, gender, ventricular fibrillation, congestive heart failure, pulmonary oedema, cardiogenic shock, other cardiac arrest and atrial fibrillation. We found that the odds ratio for death on days 6.30 was 6.34 (3.55-11.30, 95% confidence limits, P < 0.001) for patients with primary ventricular fibrillation (without heart failure) and 4.06 (2.68-6.14, P < 0.001) for patients with ventricular fibrillation secondary to heart failure compared to patients without ventricular fibrillation. For patients surviving more than 30 days, relative risk of death in those with ventricular fibrillation was 1.11 (95% confidence interval 0.93-1.34, P = 0.26). Logistic regression analysis of relative risk associated with ventricular fibrillation in time intervals, indicated that the importance of ventricular fibrillation for risk of death was exhausted during the initial 60 days after infarction.

CONCLUSION

Ventricular fibrillation is associated with an independent increased risk of death within 0-60 days after infarction. After this period, the prognosis in survivors of ventricular fibrillation does not differ significantly from patients without ventricular fibrillation.

Clinical characteristics, left and right ventricular ejection fraction, and long-term prognosis in patients with non-insulin-dependent diabetes surviving an acute myocardial infarction

Patients with diabetes mellitus have a high morbidity and mortality from acute myocardial infarction, the reason for which is not fully understood. The relationship between congestive heart failure symptoms, left ventricular ejection fraction, and long-term mortality was examined in 578 hospital survivors of acute myocardial infarction, 47 of whom had Type 2 (non-insulin-dependent) diabetes mellitus. None of the patients were treated with insulin. The prevalence of congestive heart failure during hospitalization was similar in patients with and without diabetes, although mean diuretic dose was higher in the former patients. Left and right ventricular ejection fraction was measured with radionuclide ventriculography in the second week after acute myocardial infarction. At discharge from the coronary care unit, patients with and without diabetes had similar left ventricular ejection fraction (with diabetes: median 46% vs without diabetes: median 43%; p = 0.89). Median right ventricular ejection fraction (62%) was within normal limits in both groups and did not differ statistically. Survival data were obtained for all patients. The 5-year mortality was increased in patients with diabetes compared with non-diabetic patients independent of left ventricular ejection fraction. Univariate analysis showed that the cumulative 5-year mortality rate was 53% in the group with diabetes compared with 43% in the non-diabetic group (p = 0.007). Using multivariate regression analysis presence of diabetes was found to have a significant association with long-term mortality after myocardial infarction, that was independent of age, history of hypertension, congestive heart failure symptoms during hospitalization or of either left or right ventricular ejection fractions at discharge. We conclude that the excess mortality in patients with non-insulin-dependent diabetes mellitus is not explained by available risk markers after myocardial infarction. Even though left ventricular ejection fraction and serum creatinine did not differ significantly, the apparent higher dose of Frusemide in patients with than without non-insulin-dependent diabetes mellitus might indicate that heart failure, it present, is more severe in patients with than in those without diabetes. The importance of diastolic dysfunction in this context needs to be determined.

Prognostic value of echocardiography compared to other clinical findings. Multivariate analysis based on long-term survival in 456 patients

The prognostic significance of conventional clinical and echocardiographic data in patients referred to echocardiography was retrospectively analyzed. 456 patients (206 females and 250 males) were studied in the department of cardiology in a district hospital. Survival after 3 years was 64%. By multivariate analysis five factors contained independent, significant, prognostic information (hazard ratios for death are given in parentheses): left ventricular wall motion score index (WMI) < or = 1.2 by echocardiography (2.5), status as inpatient (2.1), age > 65 years (1.7), clinical heart failure (1.9) and atrial fibrillation (1.5). A stepwise multivariate analysis was performed by entering variables into a model initially forced to contain information on age, hospitalization status, treatment of heart failure and heart rhythm. In this analysis, a poor WMI (< or = 1.2) and a dilated right ventricle contained further independent prognostic information. In conclusion, among conventional clinical and echocardiographic data, WMI was the most powerful predictor of long-term survival, and despite knowledge of major clinical features echocardiography provided further prognostic information.

Improving long-term survival of patients with acute myocardial infarction from 1977-1988 in a region of Denmark

The aim of this investigation was to study secular trends in long-term survival following myocardial infarction (MI). Five thousand one hundred and fifty-seven consecutive cases of MI in 3942 patients were recorded in a well-defined region in the study period 1977-1988. The study period ended before thrombolytic therapy was introduced in the hospital. One and 5-year survival (+/- 95% confidence limits) was 61 +/- 2% and 42 +/- 2% in 1977-1980. These figures changed to 61 +/- 2% and 44 +/- 2% in 1981-1984, and to 64 +/- 2 and 46 +/- 2% in 1985-1988. The improvement with time was statistically significant (P < 0.001). In a Cox proportional hazard model, time of infarction was an independent predictor of survival. Patients were subdivided into a high risk group suffering from either congestive heart failure or cardiac arrest during hospitalization, and a low risk group without these complications. Year of infarction was without importance in the high risk group but highly significant in the low risk group. Long-term survival following MI gradually improved prior to the introduction of thrombolytic therapy. The improvement was confined to low risk patients without cardiac arrest or congestive heart failure.

Myocardial infarction 1979-1988 in Denmark: secular trends in age-related incidence, in-hospital mortality and complications

All admissions to a coronary care unit (CCU) in Copenhagen County were prospectively registered over a 10-year period, from 1979 to 1988, i.e. after the introduction of CCUs but before the era of intervention with thrombolytic or prophylactic medical treatment. The catchment area remained nearly constant throughout the study period; all patients with MI were admitted to the CCU regardless of age and concomitant diseases, and treatment and discharge policy of the department was unchanged. A total of 4176 MI admissions were registered. During the study period, the age-specific incidence of MI decreased in males above 50 years of age, but was virtually unchanged in females, increasing the proportion of women in the MI population from 26 to 33%. In-hospital and 30-day mortality was unchanged. The occurrence of atrial fibrillation during the admission increased significantly (from 11 to 18%), while the incidence of ventricular fibrillation, heart failure and pulmonary oedema was unchanged.

Aortic dissection in the thrombolytic era: early recognition and optimal management is a prerequisite for increased survival

Based on two case reports, problems of diagnosis and treatment of aortic dissection are discussed. Thrombolytic treatment given to patients with aortic dissection presenting symptoms mimicking acute MI seems to have a fatal outcome. Indications, as well as contra-indications, for thrombolytic therapy are therefore of great importance, when this treatment is given to patients suspected of having acute myocardial infarction, especially where diagnosis is uncertain or as prehospital treatment. In patients with chest pain symptoms without typical history and electrocardiographic changes the diagnosis should be reconsidered within a few hours and, if possible, together with echocardiographic findings. In doing so patients with coronary heart disease will get all the benefits of thrombolytic treatment. Furthermore the importance of quick accurate diagnosis, especially in type A aortic dissection is pointed out, as emergency surgical intervention can be lifesaving. A more aggressive medical and surgical approach has contributed to the improved survival among patients with aortic dissections.

Reduced infarct size in nonreperfused myocardial infarction by combined infusion of isosorbide dinitrate and streptokinase

The value of thrombolytic therapy in myocardial infarction is well established, while any beneficial effect of adjunct therapy is more uncertain. In a double-blind, randomized, parallel-group study the effect of combined intravenous infusions of streptokinase and isosorbide dinitrate (ISDN) on enzyme-estimated infarct size was investigated. One hundred consecutive patients with strong clinical and electrocardiographic suspicion of myocardial infarction, admitted to the coronary care unit within 8 hours after the onset of symptoms, were given a streptokinase infusion of 1.5 million units for 1 hour and a titrated dose of ISDN or placebo for 48 hours. From isoenzyme B of creatine kinase (CK-B) values measured every 4 hours, the infarct size was calculated and the possible presence of reperfusion was evaluated. The infarct size in patients receiving ISDN infusion was reduced (p = 0.04, one-sided test) compared with placebo. By subdividing the patients according to whether or not reperfusion had occurred, the infarct size appeared to be similar following ISDN and placebo in patients with reperfusion (419 versus 369 U/L), whereas the infarct size in patients not reperfused was markedly reduced after treatment with ISDN (223 versus 1320 U/L, p = 0.003). In conclusion, the present study demonstrates that the infarct size may be reduced by other means than reperfusion and it supports the use of combined infusion of thrombolytic agents and nitrates in patients with suspected myocardial infarction.

Estimation of granulocyte and lymphocyte potassium in normal subjects and in patients treated with diuretics because of cardiovascular disease: a methodological study

A method is described for measuring the potassium content in leukocytes using Percoll (R) density gradient centrifugation. Ninety subjects between 21 and 92 years formed the reference population. The magnesium content in leukocytes could not be estimated because of interaction between the ion and the Percoll (R) media. Sex, age, leukocytosis because of infection, physical stress, venous stasis did not interfere with the analysis. The potassium content was calculated per cell and per g-1 of DNA. The granulocyte potassium content was (median (range)) 37.4 (25.8-75.0) fmol/cell-1 or 2.9 (1.5-9.8) mmol g-1 DNA. The lymphocyte potassium content was 45.9 (26.4-69.6) fmol cell-1 or 3.3 (1.5-5.0) mmol g-1 DNA. The coefficient of variation (less than 10%) was not reduced by using cell DNA instead of cell number as reference. The interindividual variation was high, making the test unfit for clinical use. The leukocyte potassium content was not decreased in patients with acute myocardial infarction nor in patients treated with diuretics and potassium supplements because of cardiovascular disease.

Plasma zinc concentrations during the first 2 years after diagnosis of insulin-dependent diabetes mellitus: a prospective study

Studies of zinc status in insulin-dependent diabetes mellitus (IDDM) have shown contradictory results. Zinc is essential for many enzymes involved in the human metabolism and may play a role in the biosynthesis and storage of insulin in the B-cell. We therefore prospectively followed 26 patients (14 males and 12 females) with newly diagnosed IDDM in order to determine the plasma zinc variation at the time of diagnosis and after 1, 3, 6, 12 and 24 months. Seventy-two healthy persons (36 males and 36 females) served as controls. Only minor differences in plasma zinc were demonstrated during the first 2 years of IDDM. A sex difference was found in healthy controls but only after 24 months in the diabetics. Quantitative changes of the B-cell function, development of insulin antibodies, age, body weight and serum albumin did not correlate with the course of plasma zinc.

Myocardial contractility and performance capacity after magnesium infusions in young healthy persons: a double-blind, placebo-controlled, cross-over study

To evaluate the effect of intravenous magnesium (Mg) treatment on the inotropic state of the heart and maximal work capacity, 9 healthy volunteers were entered in a double-blind, placebo-controlled, cross-over study. Separated by an interval of three weeks, the volunteers were tested twice, each time randomly allocated to receive either an intravenous injection of 10 mmol magnesium chloride dissolved in 100 ml isotonic sodium chloride or placebo of isotonic sodium chloride only. Before and after each infusion myocardial inotropism was evaluated by echocardiography. Mitral-septal distance (MSA) was used as a measure for ejection fraction. On each test day an ergometer bicycle exercise test was performed, and maximal work capacity was calculated. Magnesium treatment reduced the MSA (from 4.2 to 2.9 mm, p = 0.07), while no difference was found after placebo treatment. Likewise, a tendency toward increasing fractional shortening after magnesium treatment was detected, although this difference was not statistically significant (p = 0.1). No difference in maximal work capacity between the magnesium and placebo periods was found. Serum magnesium concentrations and placebo periods was found. Serum magnesium concentrations rose significantly after the infusions (from 0.82 to 1.38 mmol/l, p less than 0.001). It is concluded that intravenous magnesium does not exert a negative inotropic effect on the myocardium as previously stated. On the contrary, we found a tendency toward a positive inotropic effect. However, the observed differences are of borderline statistical significance and a more extended study, employing invasive measurements of cardiac inotropism appears to be necessary.