Respiratory disorders , particularly worsening of COPD , were the most common adverse events ( COPD : indacaterol , 747 [ 43 % ] of 1721 patients and tiotropium , 665 [ 39 % ] of 1718 patients ) and serious adverse events ( COPD : indacaterol , 147 [ 9 % ] of 1721 patients and tiotropium , 121 [ 7 % ] of 1718 patients ) .