The incidence of coronary artery disease in patients with symptomatic bradyarrhythmias

Impact of mild cognitive impairment on unplanned readmission in patients with coronary artery disease

AIMS

To investigate the effect of mild cognitive impairment (MCI) on unplanned readmission in patients with coronary artery disease (CAD).

METHODS AND RESULTS

From 2132 CAD patients, MCI was estimated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J) in 243 non-dementia patients who met the study criteria. The primary outcome was unplanned hospital readmission after discharge. The incidence of MCI in this cohort was 33.3%, and 51 patients (21.0%) had unplanned readmission during a mean follow-up period of 418.6 ± 203.5 days. After adjusting for the covariates, MCI (hazard ratio, 2.28; 95% confidence interval: 1.09-4.76; P = 0.03) was independently associated with unplanned readmission in the multivariable Cox proportional hazard regression analysis. In the Kaplan-Meier analysis, the cumulative incidence of unplanned readmission for the MCI group was significantly higher than that for the non-MCI group (log-rank test, P < 0.001). Even after exclusion of the patients readmitted within 30 days of discharge, the main results did not change (log-rank test, P < 0.001).

CONCLUSION

Mild cognitive impairment was independently associated with unplanned readmission after adjustment for many independent variables in CAD patients. In addition to its short-term effects, the adverse effects of MCI had a persistent, long-term impact on CAD patients. Assessment of cognitive function should be conducted by health professionals prior to hospital discharge and during follow-up. To prevent readmission of CAD patients, it will be necessary to support solutions to the problems that inhibit secondary prevention behaviours based on the assessment of the patients' cognitive function.

Coexistent coronary artery disease in Indian patients undergoing permanent pacemaker implantation (PPI) for symptomatic bradyarrhythmia

Background

The cause-effect of conduction disturbance in chronic lesion of coronary arteries is complicated. This study was designed to evaluate coexistent CAD in patients with symptomatic bradyarrhythmia to find common anatomic basis for conduction disturbances and its relationship to conventional coronary risk factors.

Methods

In this prospective observational study, 929 patients who admitted for symptomatic bradyarrhythmia requiring permanent pacemaker implantation were included. All included patients underwent coronary angiography and were divided into groups based on angiographic findings. Association between conduction disturbances and these groups were analyzed.

Results

A total of 929 patients with mean age of 63.1 years were included in our study. We found age ≥50 years, male sex, presence of diabetes and hypertension as statistically significant predictors of abnormal coronary angiography. Obstructive CAD (≥50% stenosis) was found in 34.4% patients. Prevalence of single vessel disease, double vessel disease and triple vessel disease was 15.3%, 10.2% and 8.9% respectively. Severe coronary obstruction (≥90% obstruction) was found in 16.25% patients. Revascularization was advised in three fourth of cases of obstructive CAD. Approximately two third of patients didn’t have significant obstruction in coronaries supplying the conduction system. Type 4 was the commonest anatomy in obstructive CAD. SA Nodal artery was found more diseased in patients of SSS with p value of 0.01.

Conclusion

Obstructive CAD was found in one third of patients undergoing PPI. Age ≥50 years, male sex, diabetes and hypertension were found significantly correlated with presence of CAD and may act as important markers for the judgment of further coronary evaluation.

Risk factors and a 3-month risk score for predicting pacemaker implantation in patients with atrial fibrillations

Objectives

To identify risk factors and to develop a predictive risk score for pacemaker implantation in patients with atrial fibrillation (AF).

Methods

Using Danish nationwide registries, patients with newly diagnosed AF from 2000 to 2014 were identified. Cox proportional-hazards regression computed HRs for risk factors of pacemaker implantation. A logistic regression was used to fit a prediction model for 3-month risk of pacemaker implantation and derived a risk score using 80% of the data and its predictive accuracy estimated using the remaining 20%.

Results

Among 155 934 AF patients included, the median age (IQR) was 75 (65–83) and 51.3% were men. During a median follow-up time of 3.4 (1.2–5.0) years, 8348 (5.4%) patients received a pacemaker implantation. Risk factors of pacemaker implantation were (in order of highest risk first) age above 60 years, congenital heart disease, heart failure at age under 60 years, prior syncope, valvular AF, hypertension, ischaemic heart disease, male sex and diabetes mellitus. The derived risk score assigns points ranging from 1 to 14 to each of these risk factors. The 3-month risk of pacemaker implantation increased from 0.4% (95% CI: 0.2 to 0.8) at 1 point to 2.6% (95% CI: 1.9 to 3.6) at 18 points. Area under the receiver operator characteristics curve was 62.9 (95% CI: 60.3 to 65.5).

Conclusion

We highlighted risk factors of pacemaker implantation in newly diagnosed AF patients and created a risk score. The clinical utility of the risk score needs further investigation.

Deactivation vs. asynchronous pacing - prospective evaluation of a protocol for rhythm management in patients with magnetic resonance conditional pacemakers undergoing adenosine stress cardiovascular magnetic resonance imaging

Background

Cardiovascular Magnetic Resonance (CMR) imaging with adenosine stress is an important diagnostic tool in patients with known or suspected coronary artery disease (CAD). However, the method is not yet established for CAD patients with pacemakers (PM) in clinical practice. A possible reason is that no recommendations exist for PM setting (paused pacing or asynchronous mode) during adenosine stress. We elaborated a protocol for rhythm management in clinical routine for PM patients that considers heart rate changes under adenosine using a test infusion of adenosine in selected patients.

Methods

47 consecutive patients (mean age 72.3 ± 10,0 years) with MR conditional PM and known or suspected CAD who underwent CMR in clinical routine were studied in this prospective observational study. PM indications were sinus node dysfunction (SND, n = 19; 40,4%), atrioventricular (AV) block (n = 26; 55.3%) and bradyarrhythmia in permanent atrial fibrillation (AF, n = 2; 4.3%). In patients with SND, normal AV-conduction and resting HR >45 bpm at the time of CMR and in AF the PM was deactivated for the scan. In intermittent AV-block a test infusion of adenosine was given prior to the scan. All patients with permanent higher degree sinuatrial or AV-block or deterioration of AV-conduction in the adenosine test were paced asynchronously during CMR, in patients with preserved AV-conduction under adenosine the pacemaker was deactivated. CMR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement.

Results

The adenosine test was able to differentiate between mandatory PM stimulation during CMR and safe deactivation of the device. In patients with permanent sinuatrial or AV-block (n = 11; 23.4%) or deterioration of AV conduction in the adenosine test (n = 5, 10.6%) asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm, no competitive stimulation was seen during the scan. 10 of 15 (66,7%) patients with intermittent AV-block showed preserved AV-conduction under adenosine. As in SND and AF deactivation of the PM showed to be safe during CMR, no bradycardia was observed.

Conclusion

Our protocol for rhythm management during adenosine stress CMR showed to be feasible and safe and may be recommended for pacemaker patients undergoing routine CMR.

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24^-/- mouse model of HGPS. Challenge of Zmpste24^-/- mice with the β-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24^-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24^-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.

Prevalence and characterization of coronary artery disease in patients with symptomatic bradyarrhythmias requiring pacemaker implantation

Background

This study was conducted to assess the prevalence and characterization of CAD in high risk patients requiring pacemaker implantation for symptomatic bradyarrhythmias.

Methods

This study included 100 patients with symptomatic sinus node dysfunction or atrioventricular block, who were at high risk of CAD or had previously documented atherosclerotic vascular disease (ASCVD). Coronary angiography was performed before pacemaker implantation. CAD was defined as the presence of any degree of narrowing in at least one major coronary artery or its first order branch. Obstructive CAD was defined as ≥50% diameter stenosis. CAD was categorized as single vessel disease (SVD), double vessel disease (DVD), or triple vessel disease (TVD); and obstructive CAD in the arteries supplying the conduction system was sub-classified according to Mosseri's classification.

Results

Out of 100 patients (mean age 64.6 ± 10.7 years), 45 (45%) had CAD. 29% patients had obstructive CAD while 16% had non-obstructive CAD. 53.3% patients had SVD, 15.6% had DVD and 31.1% had TVD. Among patients with obstructive CAD; Type I, II, III and IV coronary anatomies were present in 6.9%, 34.5%, 10.3% and 48.3% patients respectively. Presence of CAD significantly correlated with dyslipidemia (p = 0.047), history of smoking (p = 0.025), and family history of CAD (p = 0.002).

Conclusion

Angiographic CAD is observed in a substantial proportion of patients with symptomatic bradyarrhythmias and risk factors for CAD. It could be argued that such patients should undergo a coronary work-up before pacemaker implantation. Treatment of concomitant CAD is likely to improve the long term prognosis of these patients.

Feasibility and safety of adenosine cardiovascular magnetic resonance in patients with MR conditional pacemaker systems at 1.5 Tesla

BACKGROUND

Cardiovascular Magnetic Resonance (CMR) with adenosine stress is a valuable diagnostic tool in coronary artery disease (CAD). However, despite the development of MR conditional pacemakers CMR is not yet established in clinical routine for pacemaker patients with known or suspected CAD. A possible reason is that adenosine stress perfusion for ischemia detection in CMR has not been studied in patients with cardiac conduction disease requiring pacemaker therapy. Other than under resting conditions it is unclear whether MR safe pacing modes (paused pacing or asynchronous mode) can be applied safely because the effect of adenosine on heart rate is not precisely known in this entity of patients. We investigate for the first time feasibility and safety of adenosine stress CMR in pacemaker patients in clinical routine and evaluate a pacing protocol that considers heart rate changes under adenosine.

METHODS

We retrospectively analyzed CMR scans of 24 consecutive patients with MR conditional pacemakers (mean age 72.1 ± 11.0 years) who underwent CMR in clinical routine for the evaluation of known or suspected CAD. MR protocol included cine imaging, adenosine stress perfusion and late gadolinium enhancement.

RESULTS

Pacemaker indications were sinus node dysfunction (n = 18) and second or third degree AV block (n = 6). Under a pacing protocol intended to avoid competitive pacing on the one hand and bradycardia due to AV block on the other no arrhythmia occurred. Pacemaker stimulation was paused to prevent competitive pacing in sinus node dysfunction with resting heart rate >45 bpm. Sympatho-excitatory effect of adenosine led to a significant acceleration of heart rate by 12.3 ± 8.3 bpm (p < 0.001), no bradycardia occurred. On the contrary in AV block heart rate remained constant; asynchronous pacing above resting heart rate did not interfere with intrinsic rhythm.

CONCLUSION

Adenosine stress CMR appears to be feasible and safe in patients with MR conditional pacemakers. Heart rate response to adenosine has to be considered for the choice of pacing modes during CMR.

Sinus dysfunction after stent implantation in the right coronary artery immediately recovered after reflow in the sinus node artery

A 67-year-old man who had a history of syncope was admitted because of effort angina. The sinus node (SN) was the single blood supply from the right coronary artery (RCA). After we implanted 2 everolimus-eluting stents for RCA, slow-flow occurred and the SN artery was occluded, and junctional escape rhythm was sustained. After the wiring to the occluded SN artery, junctional escape rhythm immediately recovered to sinus rhythm, and the patient achieved continuous sinus rhythm and stable hemodynamics. Given that acute SN ischemia is a possible cause of sinus dysfunction, careful choice of a percutaneous coronary intervention strategy should be taken into consideration if the SN artery is the single blood supply from the RCA and if syncopal history is present.

Left atrial myxoma with neovascularization presenting as a sick sinus syndrome

Myxoma is benign tumor of the heart. It is mostly located in the left atrium and revascularized by the left and right coronary artery in 30% to 40% of cases. Symptoms of these neovascularized cardiac myxomas are typically quite variable, from obstruction of mitral valve to coronary embolism resulting in acute myocardial infarction. In this case, left atrial myxoma that is revascularized by nodal branches of the right coronary artery presented as a sick sinus syndrome, which is rare in literature.

Transient presyncope secondary to posterior descending artery occlusion

We describe the case of a 64-year-old male initially presenting with presyncope and bradycardia, without any anginal symptoms or objective evidence of myocardial ischemia. A stress test induced no physical symptoms but revealed a left bundle branch block with multiple preventricular contractions on electrocardiogram. Subsequent catheterization revealed severe obstructive disease throughout the coronary arteries. He was treated percutaneously on two separate heart catheterizations. The presyncope and bradycardia resolved after reperfusion of the posterior descending artery.

Pacemaker Infections: A 10-Year Experience

BACKGROUND

Infection is a major complication of pacemaker and defibrillator (PPM/ICD) implantation. The experience in an Australian regional centre is reported.

METHODS

Ten years' (1994-2004) cases of PPM/ICD infection retrospectively analysed and compared to overall insertion data; management and outcomes examined.

RESULTS

A total 39 cases (79.5% male, median age 71.3 years) identified, 24 in the primary centre where 1481 procedures performed (infection rate 1.6%). Patients with infection had average 2.2 procedures performed (odds ratio for infection if >1 procedure=4.7); 14 (36%) first implantations, 35 (90%) pacemakers, 11 (28%) recurrent. No difference in operation duration or difficulty between infected and non-infected cases. Infection in 18 cases (46%) involved lead/s, 16 (41%) generator and 5 (13%) both. Median time to presentation was 7.9 months. Echocardiography demonstrated lead vegetations in 8 cases. Organisms identified in 25 (64%)-92% Staphylococci (65% S. aureus); blood cultures positive in 18. PPM/ICD removed in 26 (67%), including lead/s in 89%; average hospital stay 37 days. One death attributable to PPM/ICD infection (mortality 2.6%), median follow-up 29.3 months.

CONCLUSIONS

A PPM/ICD infection rate of 1.6% (endocarditis 0.3%) demonstrated. Second and subsequent procedures carried almost 5 times greater infection risk.

Acute thrombosis of the sinus node artery: arrhythmological implications

A 53 year old woman was referred for percutaneous coronary intervention because of a recent inferior myocardial infarction. During right coronary artery stent implantation, intermittent occlusion of the coronary side branch for the sinus node occurred, associated with intermittent sinus arrest and junctional escape rhythm. This led to speculation about the potential mechanisms for sinus node dysfunction. Degenerative fibrosis of nodal tissue is actually considered the most common cause of bradyarrhythmias. Yet, in everyday practice, no particular attention is usually paid to other potential pathogenic mechanisms such as coronary artery disease. This may be particularly true for elderly patients or patients with multiple risk factors. Thus, sinus node dysfunction may be an unrecognised marker of coronary artery disease.