Risk factors for mortality within one-year after implantable cardioverter defibrillator implantation: a nationwide study

Background

Current guidelines do not recommend implantable cardioverter defibrillator (ICD) implantation in patients with an estimated survival probability of less than one year. There is still an unmet need to identify patients who are unlikely to benefit from an ICD.

Purpose

We determined one-year mortality after ICD implantation and associated risk factors of one-year mortality.

Methods

Using Danish nationwide registries from 2000–2016, we identified patients ≥18 years old undergoing first-time ICD implantation for primary or secondary prevention. Patients were followed for up to one-year from time of ICD implantation. Risk factors associated with one-year mortality after time of ICD implantation were evaluated in multivariable logistic regression models.

Results

A total of 13,344 patients underwent first-time ICD implantation (median age: 66 years [25th-75th percentile 58–72 years], male=81.3%, secondary prevention=54.6%), of which 647 died (4.8%) within one year of follow-up. Compared with ICD patients who survived for one year, those who died were significantly older (72 years vs. 66 years, p<0.001) and had more comorbidities, including congestive heart failure (70.8% vs. 63.4%), atrial fibrillation (36.6% vs. 23.6%), diabetes (30.8% vs. 19.9%), chronic obstructive pulmonary disease (COPD) (17.0% vs. 8.2%), chronic renal disease (13.0% vs. 4.4%), malignancy (9.9% vs. 5.4%), and dialysis (7.3% vs. 2.4%) (p<0.001 for all).

Results from the multivariable logistic regression model are depicted in the Figure. There was a graded relationship between age and one-year mortality, with a greater risk of all-cause mortality with increasing age.

In addition, dialysis, chronic renal disease, COPD, malignancy, diabetes, and congestive heart failure were strongly associated with increased risk of one-year all-cause mortality. However, ischaemic heart disease was associated with a lower risk of all-cause mortality (Figure). The one-year risk of death was 13.2% for both patients receiving dialysis and patients with chronic renal disease, respectively.

The majority of deaths within one year were attributed to cardiovascular causes (408/647, 63.1%) of which chronic ischaemic heart disease (68/647, 10.5%), acute myocardial infarction (50/647, 7.7%), and atherosclerosis (40/647, 6.2%) were the most common. The most common non-cardiovascular cause of death was malignancy (10.5%).

Conclusion

In patients with a first-time ICD implantation, 95% survived for more than one year after implantation. While low mortality rates are indicative of relevant patient selection for ICD implantation, advanced age, dialysis, and several comorbidities were all strongly associated with increased one-year mortality, whereas ischaemic heart disease was associated with a lower risk of one-year mortality. Potential benefit of an ICD in such patients should be carefully evaluated before implantation.

Funding Acknowledgement

Type of funding source: None

Mortality after implantable cardioverter defibrillators in dialysis patients: a nationwide study

Background

Although randomized clinical trials have shown that implantable cardioverter defibrillators (ICDs) reduce mortality in selected patients, patients on dialysis are excluded from these trials. Thus, data on mortality risk after ICD implantation in these patients are sparse.

Purpose

To examine all-cause mortality in patients receiving an ICD according to dialysis status and to identify factors associated with all-cause mortality in patients on dialysis.

Methods

Using Danish nationwide registries from 2000–2017, all patients ≥18 years old undergoing first-time ICD implantation were included. Patients on dialysis were identified prior to ICD implantation and followed for up to five years. The cumulative incidence of all-cause mortality according to dialysis status was assessed. Factors associated with all-cause mortality after ICD implantation in dialysis patients were examined using multivariable Cox proportional hazard regression.

Results

A total of 14,681 ICD patients were identified, of which 218 (1.5%) were on dialysis prior to ICD implantation. Compared with ICD patients not on dialysis, those on dialysis were younger (median age 64 years [IQR: 58–70] vs. 66 years [IQR: 57–72], p=0.02), more likely to receive an ICD for secondary prophylaxis (69.7% vs 53.7%), and had more comorbidities including ischaemic heart disease (60.6% vs. 46.3%), diabetes (28.4% vs. 20.4%), and peripheral vascular disease (10.1% vs. 5.6%) (p for all <0.05).

The median time to death among ICD patients on dialysis and not on dialysis were 1.3 years (IQR: 0.4–2.8 years] and 2.2 years [IQR: 1.0–3.5 years], respectively.

One-year mortality among ICD patients on dialysis (13.0%) was significantly higher compared with ICD patients not on dialysis (4.7%), p<0.001 (Figure). Five-year mortality was significantly higher in ICD patients on dialysis than those not on dialysis (42.2% vs 23.6%), p<0.001 (Figure).

Factors associated with increased risk of all-cause mortality among ICD patients on dialysis were age ≥65 years at time of implantation (reference: age <65 years) (HR 1.90 [95% CI: 1.13–3.19]), primary prophylactic ICD (HR 1.81 [95% CI 1.08–3.05]), and diabetes (HR 1.87 [95% CI 1.14–3.07]). Sex, ischaemic heart disease, heart failure, stroke, chronic obstructive pulmonary disease, and malignancy were not associated with the risk of mortality (p>0.05 for all).

Cardiovascular causes of death were common both in patients with- and without dialysis, 69.6% and 60.0%, respectively.

Conclusion

Five-year mortality in ICD patients on dialysis was 42% and twice as high compared with ICD patients not on dialysis. Age ≥65 years, primary prophylactic indication, and diabetes were factors associated with increased mortality. Careful evaluation of the potential benefit from an ICD implantation in dialysis patients is important considering the overall high mortality rates.

Funding Acknowledgement

Type of funding source: None

194SGLT-2 inhibitors versus GLP-1 receptor agonists and risk of mortality, chronic kidney disease and hospitalisation for heart failure in patients with type 2 diabetes

Background

Two promising classes of second-line glucose-lowering drugs, the sodium-glucose cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA), have both been shown to lower the risk of cardiovascular (CV) outcomes in patients with type 2 diabetes, however no head-to-head comparisons exist.

Purpose

The aim of this study was to examine the risk of CV and all-cause mortality, incident chronic kidney disease (CKD) and hospitalisation for heart failure (HF) in association with SGLT-2i versus GLP-1RA use.

Methods

New users of SGLT-2i and GLP-1RA, with no prior use of drugs from the comparison class, were identified between 2012–2016, using individual-level linkage of Danish nationwide registries. The absolute risk of CV was calculated using the Aalen-Johansen Estimator with non-CV mortality as competing risk. The hazard ratios (HR) of CV and all-cause mortality, incident CKD and hospitalisation for HF were estimated using Cox regression and adjusted for age, sex, diabetes duration and other outcome specific risk factors.

Results

The study included a total of 8,304 SGLT-2i users (median age: 63 years [interquartile range (IQR): 54–70], males: 63%, dapagliflozin: 60.5%, empagliflozin: 36.5%) and 13,318 GLP-1RA users (median age: 60 years [IQR: 50–68], males: 54%, liraglutide: 97.4%) with a median follow-up time of 2.0 [(IQR): 1.5–2.9] years and 3.6 [IQR: 2.1–5.0] years, respectively. At baseline 29% of SGLT-2i and 30% of GLP-1RA users had CV disease. The absolute risks are shown in Figure 1. Compared with GLP-1RA, initiation of SGLT-2i was in adjusted analyses associated with a lower risk of CV mortality (HR: 0.49 [confidence interval (CI): 0.37–0.65]), all-cause mortality [HR: 0.79 [CI: 0.68–0.93], incident CKD (HR: 0.42 [CI: 0.34–0.53] and hospitalisation for HF (HR: 0.68 [CI: 0.59–0.78]).

Figure 1

Conclusion

SGLT-2i use was associated with a significantly lower risk of CV and all-cause mortality, incident CKD and hospitalisation for HF in comparison with GLP-1RA use.

Acknowledgement/Funding

The Danish Heart Foundation (18-R125-A8381-22082)