Short-term prognosis of changes in plasma potassium following an episode of hyperkalaemia in patients with chronic heart failure.

BACKGROUND/AIM: There is an increasing prevalence of chronic heart failure (HF). It is well known that patients with HF and disturbances in the potassium level have an increased mortality risk. The aim of this study was to investigate the prognosis of a second plasma-potassium measurement after an episode with hyperkalaemia on short-term mortality in patients with chronic HF. METHODS AND RESULTS: From Danish national registers, 2,339 patients with chronic HF and hyperkalaemia (>4.6 mmol/L) at first potassium measurement within 14-365 days from concomitant treatment were identified. To be included, a second measurement was required within 6-30 days subsequent to the first measurement and the 60-day mortality was observed. Based on the second measurement, the patients were divided into five groups: <3.5 mmol/L (n = 257), 3.5-4.0 mmol/L (n = 709), 4.1-4.6 mmol/L (n = 1,204, reference), 4.7-5.0 mmol/L (n = 89) and >5.0 mmol/L (n = 80). To assess all-cause and cardiovascular mortality, we used the Cox regression model. The multivariable analysis showed that patients with potassium concentrations <3.5 mmol/L (hazard ratio (HR): 3.03; 95% CI: 2.49-3.70) and 3.5-4.0 mmol/L (HR: 1.81; 95% CI: 1.54-2.14) had a worse prognosis compared to the reference. We observed similar results when calculating the risk of cardiovascular mortality. A restricted cubic spline curve showed a U-shaped relationship between plasma-potassium and all-cause mortality. CONCLUSION: Patients with chronic HF and hyperkalaemia who became hypokalaemic after 6-30 days were associated with a higher 60-day all-cause and cardiovascular mortality compared to the reference. This also applied for patients with low normal potassium concentrations (3.5-4.0 mmol/L).

Short-term prognosis of normalising serum potassium following an episode of hypokalaemia in patients with chronic heart failure.

BACKGROUND/ AIM: It is well known that patients with chronic heart failure and hypokalaemia have increased mortality risk. We investigated the impact of normalising serum potassium following an episode of hypokalaemia on short-term mortality among patients with chronic heart failure. METHODS AND RESULTS: We identified 1673 patients diagnosed with chronic heart failure who had a serum potassium measurement under 3.5 mmol/l within 14 days and one year after initiated medical treatment with both loop diuretics and angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers. A second serum potassium measurement was required 8-30 days after the episode of hypokalaemia. All-cause mortality and cardiovascular mortality was examined within 90 days from the second serum potassium measurement. Mortality was examined according to six predefined potassium groups derived from the second measurement:<3.5 mmol/l (n = 302), 3.5-3.7 mmol/l (n = 271), 3.8-4.1 mmol/l (n = 464), 4.2-4.4 mmol/l (n = 270), 4.5-5.0 mmol/l (n = 272), and 5.1-8.0 mmol/l (n = 94). We used Cox regression to estimate both all-cause mortality risk and cardiovascular mortality, with serum potassium at 3.8-4.1 mmol/l as reference. After 90 days, the all-cause mortality in the six groups was 29.5%, 22.1%, 20.3%, 24.8%, 23.5% and 43.6%, respectively. In multivariable adjusted analysis, patients with serum potassium <3.5 mmol/l (hazard ratio: 1.51; 95% confidence interval: 1.13-2.02) and serum potassium 5.1-8.0 mmol/l (hazard ratio: 2.18; 95% confidence interval: 1.50-3.17) had an increased risk of all-cause mortality compared to the reference. After 90 days, the cardiovascular mortality in the six groups was 19.2%, 17.7%, 14.4%, 18.9%, 18.8% and 34.0%, respectively. In multivariable adjusted analysis, patients with serum potassium 5.1-8.0 mmol/l (hazard ratio: 2.32; 95% confidence interval: 1.51-3.56) had an increased risk of cardiovascular mortality compared to the reference, while serum potassium <3.5 mmol/l (hazard ratio: 1.37; 95% confidence interval: 0.97-1.95) had a trend toward increased risk of cardiovascular mortality compared to the reference. CONCLUSION: Patients with chronic heart failure and hypokalaemia, who after 8-30 days remained hypokalaemic, had a significantly higher 90-day all-cause mortality risk compared to patients in the reference group (3.8-4.1 mmol/l). Patients with chronic heart failure and hypokalaemia, who after 8-30 days had the serum potassium level increased to a level within 5.1-8.0 mmol/l, had both a significantly higher 90-day all-cause mortality risk and cardiovascular mortality risk compared to patients in the reference group (3.8-4.1 mmol/l).

Long-term impact of baseline anaemia on clinical outcomes following percutaneous coronary intervention in stable angina.

BACKGROUND: In patients with stable angina (SA), the clinical benefits of percutaneous coronary intervention (PCI) reside almost exclusively within the realm of symptomatic improvement rather than improvement in hard clinical endpoints. The benefits of PCI should always be balanced against its potential short-term and long-term risks. Common among these risks is the presence of anaemia and its interaction with poor clinical outcomes and increased morbidity; this study aims to elucidate the impact of anaemia on long-term clinical outcomes of this patient group. METHODS: From Danish national registries, we identified patients with SA treated with PCI who had a haemoglobin measurement maximum of 90 days prior to PCI procedure. Anaemia was defined as haemoglobin <130 and <120 g/L in men and women, respectively. Follow-up was up to 3 years after PCI, and Cox regression was used to estimate HRs with 95% CIs of hospitalisation due to bleeding, acute coronary syndrome (ACS) and all-cause mortality in patients with anaemia compared with patients without anaemia. RESULTS: Of 2837 included patients, 14.6% had anaemia prior to PCI. During follow-up, 93 patients (3.3%) had a bleeding episode, which was higher in patients with anaemia (5.8%) compared with patients without anaemia (2.8%). A total of 213 patients (7.5%) developed ACS, which was higher in patients with anaemia (10.6%) compared with patients without anaemia (7.0%). Furthermore, 185 patients (6.5%) died, with a mortality rate of 18.1% in patients with anaemia compared with 4.5% in patients without anaemia. In multivariable analyses, anaemia was associated with a significantly increased risk of bleeding (HR 1.69; 95% CI 1.04 to 2.73; P 0.033), ACS (HR 1.47; 95% CI 1.04 to 2.10; P 0.031) and all-cause mortality (HR 2.41; 95% CI 1.73 to 3.30; P <0.001). CONCLUSION: Anaemia in patients with SA was significantly associated with bleeding, ACS and all-cause mortality following PCI.

The Association Between Serum Calcium Levels and Short-Term Mortality in Patients with Chronic Heart Failure.

BACKGROUND: Patients with chronic heart failure have vulnerable myocardial function and are susceptible to electrolyte disturbances. In these patients, diuretic treatment is frequently prescribed, though it is known to cause electrolyte disturbances. Therefore, we investigated the association between altered calcium homeostasis and the risk of all-cause mortality in chronic heart failure patients. METHODS: From Danish national registries, we identified patients with chronic heart failure with a serum calcium measurement within a minimum 90 days after initiated treatment with both loop diuretics and angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Patients were divided into 3 groups according to serum calcium levels, and Cox regression was used to assess the mortality risk of <1.18 mmol/L (hypocalcemia) and >1.32 mmol/L (hypercalcemia) compared with 1.18 mmol/L-1.32 mmol/L (normocalcemia) as reference. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. RESULTS: Of 2729 patients meeting the inclusion criteria, 32.6% had hypocalcemia, 63.1% normocalcemia, and 4.3% hypercalcemia. The highest mortality risk was present in early deaths (≤30 days), with a HR of 2.22 (95% CI; 1.74-2.82) in hypocalcemic patients and 1.67 (95% CI; 0.96-2.90) in hypercalcemic patients compared with normocalcemic patients. As for late deaths (>30 days), a HR of 1.52 (95% CI; 1.12-2.05) was found for hypocalcemic patients and a HR of 1.87 (95% CI; 1.03-3.41) for hypercalcemic patients compared with normocalcemic patients. In adjusted analyses, hypocalcemia and hypercalcemia remained associated with an increased mortality risk in both the short term (≤30 days) and longer term (>30 days). CONCLUSION: Altered calcium homeostasis was associated with an increased short-term mortality risk. Almost one-third of all the heart failure patients suffered from hypocalcemia, having a poor prognosis.

Prognostic role of serum sodium levels across different serum potassium levels in heart failure patients: A Danish register-based cohort study.

BACKGROUND: In heart failure (HF), evidence on the prognosis of simultaneously abnormal sodium and potassium levels remains unknown. Therefore, we investigated associations between sodium levels and 90-day all-cause mortality across potassium levels in HF patients. METHODS: Using Danish registers, we identified HF patients with sodium and potassium levels within 90 days following a redeemed loop diuretic prescription from 2000 to 2012. We grouped sodium (<139, 139-143, >143 mmol/L) and potassium levels (<3.5 [hypokalemia], 3.5-4.0, 4.1-4.6, 4.7-5.0, >5.0 mmol/L [hyperkalemia]). First, by adjusting for potassium groups using multivariable Cox regression, we compared mortality of sodium <139 mmol/L and >143 mmol/L with 139-143 mmol/L as reference. Second, by combining sodium and potassium groups, we compared mortality of the resulting 15 combinations using sodium 139-143 mmol/L and potassium 4.1-4.6 mmol/L as reference. RESULTS: We included 16,343 HF patients (median age: 77.0 years; males: 53.7%). When adjusting for potassium groups, sodium <139 mmol/L and >143 mmol/L were associated with excess mortality (hazard ratio [HR]: 1.91, 95% confidence interval [CI]: 1.74-2.09; HR: 1.45, 95% CI: 1.25-1.68; respectively). When stratifying across potassium groups (interaction term: P = 0.291), we observed excess mortality with hyperkalemia for sodium <139 mmol/L (HR: 3.30, 95% CI: 2.76-3.96) and >143 mmol/L (HR: 3.46, 95% CI: 2.31-5.18), whereas mortality risk was lower for sodium 139-143 mmol/L (HR: 1.67, 95% CI: 1.30-2.14). Correspondingly, hypokalemia was associated with excess mortality (<139 mmol/L: HR: 3.53, 95% CI: 2.76-4.52; 139-143 mmol/L: HR: 2.47, 95% CI: 1.88-3.24; >143 mmol/L: HR: 2.67, 95% CI: 1.73-4.12). Lowest mortality risk appeared with sodium 139-143 mmol/L combined with remaining potassium groups. CONCLUSION: Abnormal sodium is an important risk factor for mortality in HF patients receiving diuretics, and the importance is independent of potassium levels.

Associations of serum potassium levels with mortality in chronic heart failure patients.

AIMS: Medication prescribed to patients suffering from chronic heart failure carries an increased risk of impaired potassium homeostasis. We examined the relation between different levels of serum potassium and mortality among patients with chronic heart failure. METHODS AND RESULTS: From Danish National registries, we identified 19 549 patients with a chronic heart failure diagnosis who had a measurement of potassium within minimum 90 days after initiated medical treatment with loop diuretics and angiotensin converting enzyme inhibitors or angiotensin-II receptor blockers. All-cause mortality was examined according to eight predefined potassium levels: 2.8-3.4 mmol/L, 3.5-3.8 mmol/L, 3.9-4.1 mmol/L, 4.2-4.4 mmol/L, 4.5-4.7 mmol/L, 4.8-5.0 mmol/L, 5.1-5.5 mmol/L, and 5.6-7.4 mmol/L. Follow-up was 90 days from potassium measurement. We estimated the risk of all-cause mortality using multivariable adjusted Cox proportional hazard model, with normal serum potassium level at 4.2-4.4 mmol/L as reference. After 90 days, the mortality in the eight strata was 14.4, 8.0, 6.3, 5.0, 5.8, 7.9, 10.3, and 21.1% respectively. In multivariable adjusted analysis, patients with potassium levels of 2.8-3.4 mmol/L [hazard ratio (HR): 3.16; confidence interval (CI): 2.43-4.11], 3.5-3.8 mmol/L (HR: 1.62; CI: 1.31-1.99), 3.9-4.1 mmol/L (HR: 1.29; CI: 1.08-1.55), 4.8-5.0 mmol/L (HR: 1.34; CI: 1.10-1.63), 5.1-5.5 mmol/L (HR: 1.60; CI: 1.29-1.97), and 5.6-7.4 mmol/L (HR: 3.31; CI: 2.61-4.20) had an increased risk of all-cause mortality. CONCLUSION: Levels within the lower and upper levels of the normal serum potassium range (3.5-4.1 mmol/L and 4.8-5.0 mmol/L, respectively) were associated with a significant increased short-term risk of death in chronic heart failure patients. Likewise, potassium below 3.5 mmol/L and above 5.0 mmol/L was also associated with increased mortality.